Thesis written by
Richard H. Emmons
B.S. University of Southern California ,1946
M.A. Kent State University, 1950
A. Stewart, Advisor
Robert White, Head, Department of Education
Raymond M. Clark Dean of the Graduate School
L Bowman, President
The writer wishes to express his appreciation for the cooperation of the students, faculty members, and administrator of the Canton Division of Kent State University in the planetarium project reported in this thesis.
He is grateful also for the encouragement and assistance rendered by Dr. A.W. Stewart and Dr. L.L. Lowenstein who were his advisors.
TABLE OF CONTENTS
LIST OF ILLUSTRATIONS....................................v
II. THE DESIGN AND CONSTRUCTION OF THE
KENT STATE UNIVERSITY CANTON PLANETARIUM.......................................13
The Group Meeting
The Projector Head
The Projector Mounting
The Planetarium Dome
The Auxiliary Projectors
III. THE PLANETARIUM'S UTILITY AS AN INSTRUCTIONAL AID....50
IV. THE PLANETARIUM IN SCHOOL-COMMUNITY RELATIONS.........57
V. SUMMARY AND EVALUATION.................................65
LIST OF ILLUSTRATIONS
1. The Projector Head 18
2. The Projector Mounting 23
3. Erecting the Dome 30
4. The Dome Supports 34
5. A University Class Beneath the Dome 35
6. The Sunset Bulb 37
7. The Sunset Effect 38
8. Auxiliary Projectors and Clamps 42
9. The Portable Projector 44
10. A Slide Projection on the Dome 46
11. The Projector Adjusted for the North Pole 48
12. The Projector Ready for Demonstration and Adjusted
for the Latitude of Canton 49
The project described in this thesis was developed at the Canton Division of Kent State University during part of a two‑month period, October and November, 1949. The Canton Division of Kent State University was a temporary branch institution, created to meet the problem of over‑crowding of students on the main Kent campus in the years immediately following World War II. During its existence, from 1949 to 1950, it accommodated from 600 to 900 students each quarter. While many of these students were veterans, most were of normal junior college age from the Canton metropolitan area. Most of the classroom and office space was rented from the Canton Board of Education and was located in the McKinley High School Building at 800 North Market Avenue, in Canton. The building was shared by the high school and the university, the high school retaining more than three‑fourths of the used space. A large residence near‑by was rented by the university after the first year and, as "The Union Building," provided much‑needed additional office, classroom, and lounge space. The Union Building interjected something of a university atmosphere into what seemed to both students and faculty, a high school situation. The Academic offering at Kent State University Canton was limited to lower division courses, i.e., those at the freshman and sophomore levels. In this respect the Canton Division was not unlike a junior college. These courses were offered on a full‑time day and evening basis, by instructors responsible to both their respective department heads on the main campus and to the resident Kent State University Canton director. The course in which the planetarium project developed is listed in the Kent State University catalog under the Department of Chemistry, and entitled, "Introduction to Physical Science 162." It is a third quarter continuation of study in which the principles of chemistry, physics, and astronomy are introduced by lecture and demonstration, text study, and problem solving. Recitation and lecture periods total three hours each week, and each course of the sequence of three courses carries three quarter‑hours of university credit. No laboratory work is provided and the courses are not applicable toward a major or minor in either chemistry or physics. The sequence was intended as a terminal study of physical science for students in the several colleges who would not otherwise gain basic and desirable understandings and appreciations in this important field. The content of the course, "Introduction to Physical Science 162," at Kent State University Canton, consisted of two broad units, astronomy and atomic physics, which are not entirely unrelated. In order to understand the production of energy in the sun and stars it is necessary to obtain some insight into nuclear fusion; conversely, a student may enrich his understanding and appreciation of nuclear fusion if he realizes that the processes involved are currently taking place in the sun, making life possible on earth.
It was within the frame of reference of this course at Kent State University Canton, and for the immediate purpose of improving the presentation of the included study of astronomy, that the planetarium project had its inception and completion. The dictionary1 defines a planetarium as, "A model or representation of the planetary system, especially one using projectors to display the movements of celestial bodies on a hemispherical ceiling." The Kent State University Canton planetarium was of the latter type. In the Western Hemisphere there are six2 large planetaria using remarkable projectors developed by the Zeiss Optical Company of Germany.
These projectors, valued at about $200,000 each, are capable of reproducing 9000 stars, the planets visible to the naked eye, the moon and sun, their apparent motions in the sky, and many special effects. The institutions possessing these great instruments are: The Adler Planetarium, in Chicago; the Hayden Planetarium, in New York City; the Fels Planetarium, in Philadelphia; the Griffith Planetarium, in Los Angeles; the Buhl Planetarium, in Pittsburgh; the Morehead Planetarium, at Chapel Hill, North Carolina. At these theaters of the stars, demonstrations may be witnessed simultaneously by approximately five hundred people.
The audience is seated in concentric circles about the projector, within a dome about 70 feet in diameter. One or two programs are presented daily and are open to the public at a nominal admission charge.3 A Projector of moderate complexity, and valued at about $50,000 has been built by Mr. Frank D. Korkosz, Director of the Seymour Planetarium, Museum of Natural History, at Springfield, Massachusetts. Both Zeiss and Korkosz projectors use lenses in producing images.
A small, efficient, and comparatively inexpensive ($720) projector, developed by Mr. Armand Spitz and produced by Science Associates of Philadelphia, has become popular in astronomical circles both here and abroad. The basic principle involved in the Spitz projector is so simple that its origin is lost in obscurity. Pin‑holes are made in a light‑tight container in which a small bright source of light is centrally located. The holes are distributed about the source of light in the direction of the stars, and are of various sizes depending upon the relative brightness of the stars.
The Spitz projector is made in the form of a dodecagon. The well‑engineered mounting provides for the more important adjustment and motions. Approximately $ 1,000 of auxiliary equipment is available for use with Spitz projector, creating effects particularly useful in the study of celestial navigation4.
Spitz projector are installed at the following places.5 INTERNATIONAL
UNESCO Scientific Exhibition, in tour of Latin America.
UNITED STATES GOVERNMEMT
United States Navel Academy, Annapolis, Maryland
Aero Medical Research Laboratory, Naval Base, Philadelphia, Pennsylvania
United States Maritime Academy, Kings Point, New York MUSEUMS
Boston Museum of Science, Boston, Massachusetts Buffalo Museum of Science, Buffalo, New York
Children's Museum of Science, Charleston, West Virginia Everhart Museum, Scranton, Pennsylvania
Fort Worth Children's Museum, Fort Worth, Texas
Kansas City Museum, Kansas City, Missouri
Maryland Academy of Science, Baltimore, Maryland
Oregon Museum of Science and Industry, Portland, Oregon
Stamford Museum, Stamford, Connecticut
Alderson‑Broaddus College, Philippi, West Virginia
Butler University, Indianapolis, Indiana
Calvert School, Baltimore, Maryland
Eastern Mennonite College, Harrisonburg, Virginia
Friends Select School, Philadelphia, Pennsylvania
Kansas State College, Manhattan, Kansas
Madison State College, Harrisonburg, Virginia
Morgan State College, Baltimore, Maryland
Ohio State University, Columbus, Ohio
Pennsylvania State College, State College, Pennsylvania Phoenix Junior College, Phoenix, Arizona
Rhode Island State College, Kingston, Rhode Island
San Francisco City College, San Francisco California Stanford University, Palo Alto, California
University of Minnesota, Minneapolis Minnesota
University of Philippines, Manila, Philippine Islands
University of Puerto Rico, Rio Piedras, Puerto Rico
University of Southern California, Los Angeles California University of West Virginia, Morgantown, West Virginia
Wayne University, Detroit, Michigan
Western Michigan College, Kalamazoo, Michigan
In addition to these thirty‑four installations, there are others in Canada, Australia, Philippine Islands, and one in Egypt. There are two more, privately owned and operated, in Berkeley, California and Detroit, Michigan. The fact that the Spitz projector has been available only in the last few years makes this list of installations impressive. The concentration of two or more projectors in the same locality suggests the readiness with which educators have seized the planetarium idea after witnessing a demonstration.
No one at Kent State University Canton had seen a Spitz projector. Yet knowledge of the existence of the simple, effective instrument encouraged the writer to investigate the possibilities of establishing a Kent State University Canton planetarium. It was determined that the purchase of a Spitz projector could not be financed.
In May, 1949 a field trip and magazine article stimulated the Kent State University Canton planetarium idea. On May 1 more than fifty Kent State University Canton students and faculty members voluntarily set aside the Sunday and traveled nearly two hundred miles, to visit the nearest planetarium, ‑‑ the Buhl Planetarium at Pittsburgh. All who participated felt that they had had a pleasant and significant experience, well worth the time and money expended. The demonstration required about one hour and during this time only a few of the functions of the great Zeiss projector were used and only a few of the introductory principles of astronomy were presented. There was no opportunity for the audience to ask questions. The writer, who had previously visited the Fels planetarium and the Griffith planetarium, regarded the lecture and demonstration as excellent as any he had witnessed but agreed with certain others in attendance that the great facilities there had not been used at the maximum educational efficiency. This Difficulty seems inherent in such institutions having high maintenance expenses partly defrayed by paid admissions. Patrons must be induced to return. The programs must change periodically, as in all theaters, while the ideal demonstration for the adult novice is unchanging.
The visit had several results. first, the writer saw clearly that a small school planetarium might accomplish virtually as much as that accomplished by a typical visit to a large planetarium. Second at Kent State University Canton interest in astronomy in general, and in planetaria in particular, has been aroused. Too much had been left unanswered and several students again visited the Buhl Planetarium in the weeks following. The desirability of a Kent State University Canton planetarium became apparent.
In a magazine received at the Kent State University Canton
library at this opportune time, there appeared a brief note, barely two hundred words in length, describing a planetarium projector fashioned from simple materials by Mr. William Calder of the Department of Physics and Astronomy at Agnes Scott College
in Decatur, Georgia. The principle involved was the same used in the Spitz projector, described earlier, except for the light‑tight container Mr. Calder employed an aluminum globe. For all such projectors a hemispherical screen is almost a necessity in order to avert objectionable distortion. Mr. Calder, with resourcefulness, used a war surplus parachute as a screen, suspending it and holding it in approximate hemispherical form by several hundred strings6
The little article established the fact that a planetarium could be satisfactorily made, without much expense and without special mechanical experience, if patience, directed effort and an understanding of elementary astronomy were employed. The writer was convinced that students would benefit if they were invited to assist in a planetarium construction project. But as the academic year was then almost at an end nothing was said or done about such a project until the University opened in the fall.
Among the fifteen students enrolled in the course, "Intro‑ duction to Physical Science 162,” offered in the fall of 1949, there were several who had participated in the field trip experience the previous spring, and who were enthusiastic about the Buhl Planetarium. They had taken a hobby interest in astronomy and this was a very essential factor in the student participation in the Kent State University Canton planetarium project. The writer, as instructor of the course, could not reasonably have required his students to undertake such a project as the time and effort involved were not in proportion to the course credit. Furthermore, this would have resulted in an undue and unintended emphasis on the single unit of astronomy. Instead, the writer waited until the field trip was mentioned in class. A discussion developed in which the Buhl Planetarium was described by one of the students who had been there. The advantage of such a device in making clear the very principles we were then studying became apparent to everyone in the small informal class. At this point the writer mentioned that he believed a group of interested students might help to provide Kent State University Canton with a planetarium. The matter would have ended there, so far as the class was concerned, if it had not been for the response of the students. Their questions were met with the suggestion that those really interested arrange a time and place of meeting where the problems involved might be considered. It was informally decided that the voluntary meeting be held in the union building, Friday evening, October 13.
In addition to the writer the following persons attended the meetings: Richard Fritsche, Stanley Spring, Robert Zartmen,
Albert Totten, Harold Ludden, and Robert Stano. The original group was joined a few days thereafter by other physical science students, Theodus Cook and Gene Shackle. Walter Cunningham and Earl Walters, of Canton, although not students, later furnished the writer with outside engineering and material assistance on the projector's mounting at modest remuneration. Mr. John Paulson, a former student of astronomy, generously cooperated in the solution of the problem by providing a hemispherical screen, and Mrs. Florence Lewis, art instructor, and Mary Sabate and Marilyn Colaner, students, designed an produced a silhouette skyline of black paper which was then pasted about the base of the dome to add to the realistic effect.
For their continuous cooperation during the construction of the planetarium, this group deserves much credit. Mr. C. M. Schindler, Director of Kent State University, Canton, gave both approval and encouragement without which the planetarium could not have been given location or placed in use. And were it not for the generous cooperation, often at the expense of personal inconvenience, of several of the writer's colleagues on the Kent
State University Canton faculty, the utility of the planetarium
would have been greatly limited.
THE DESION AND CONSTRUCTION OF THE KENT STATE UNIVERSITY CANTON PLANETARIUM The Group Meeting.
The decision to undertake the construction of a planetarium to be used at the Canton Division of Kent State University was reached during the voluntary meeting held October 13, 1949, and attended by the writer and six of his students. At this meeting the writer outlined the nature of the project and, by means of a prepared punched cardboard and flashlight, demonstrated the simple principle by which star images could be produced on the ceiling. A general discussion followed concerning the necessity of a hemispherical screen, the desired movements of the projector, the types of materials to be used, the source of the materials and some details of the design. The writer advised the group to recognize and consider their time and resource limitations and to develop only modest plans and to carry these to completion. He proposed that the projector mounting be contrived from pipe fittings; that movements be accomplished by hand turning; that illumination be of the flashlight type, and that the hemispherical screen be made from wallpaper supported by easily bent aluminum such as clothesline wire. The students present believed that with their interest and resourcefulness they could develop a more ambitious design. At that time they were not able to specify the details. It was decided that the problem should be distributed according to individual interest or further study. The writer was to receive recommendations and, through personal conferences, coordinate all activities on the project. Work sessions were arranged as the design details were determined and the materials secured. Mr. Richard Fritsche agreed to study the problem of providing the hemispherical screen. Mr. Harold Ludden was particularly interested in providing a better projector mounting than the one suggested and offered to investigate the possibility and cost of outside mechanical help. Mr. Albert Totten volunteered to work out the problem of lighting effects. Altogether the meeting lasted two hours and ended in a spirit of enthusiasm and determination.
The Design and Construction of the Projector Head
For simplicity it was agreed that the projector head consist of a twelve‑inch diameter terrestrial globe owned by the writer, in which holes would be drilled according to the position and brightness of the more conspicuous stars. Stellar magnitudes of the first, second and third rank were considered adequate for the purpose of portraying the constellations. Work sessions were arranged at the Union Building and tools were provided by the writer. First, extensive experiments were conducted by flashlight, various drills and cardboard, to assure the feasibility of this globe. Drill sizes for the various stellar magnitudes had to be determined, taking into account that many planetarium demonstrations might be given in the daytime under conditions of incomplete darkness. The objective was to preserve realism in the ratio of the intensity of starlight and skylight. A projection distance of six feet was used in these quantitative experiments, according to design information obtained from other project workers. The experiments confirmed the belief that the proposed globe was satisfactory and that the optimum drill sizes for the first three stellar magnitudes were, respectively, 3/32, 1/16, and 1/32 inch diameter. The writer pointed out that these experimental results were consistent with illumination theory according to which the effective intensity of such small images is proportional to the cross‑ sectional area of the beam of light. The students who were then studying astronomy knew many of the constellations from observations out‑of‑doors but this alone was not enough to enable them to make an accurate planetarium projector. A catalog of stellar positions and magnitudes was a necessary reference. The writer selected and provided such a catalog7 and explained how it could be used. In plotting the stars on the globe the terrestrial longitude and latitude markings proved indispensable. The difficulty was in transforming coordinates from celestial to terrestrial spheres. Looking in upon the sphere, the universe had to be turned inside out. The writer developed the necessary conversion technique and explained this in detail to the students. The right ascensions, given in units of hours and minutes, had to be reexpressed in degrees, allowing fifteen degrees per hour, one degree per four minutes. These results were to be subtracted from three hundred sixty degrees before plotting as west longitude. Declinations, given in conventional angular measure in degrees north or south of the celestial equator, could be plotted directly as latitude.
It was suggested that the tedious work of preparing the projector head be accomplished by the assembly line technique. Accordingly, Mr. Robert Zartman began the task of transforming coordinates; Mr. Robert Stano and Mr. Albert Totten alternately plotted and checked; and Mr. Spring did the actual drilling. For efficiency, stars were selected in order of increasing right ascension within each magnitude. All of these above experiments and the necessary organization were established during the first work session, plus the plotting of twenty‑one stars of the first magnitude. After the fourth session all the stars of the first three magnitudes were represented, and approximately one hundred stars of the fourth magnitude were added with a needle to improve the constellation outlines. The supporting base of the terrestrial model, which had been left attached throughout this work, was then sawed off, leaving large holes at each pole (see fig. 1). A metal cap was fixed over the hole at the north pole and the North Star was plotted and drilled. A system of cardboard reinforcements was discovered within the globe which would render the globe useless as a projector. These were twisted, torn, and removed through the hole at the south pole by wire probes and long thin pliers. A flashlight was inserted into the globe through the hole at the south pole. The room was then darkened and the first projection was made against the walls and ceilings. In spite of the distortion caused by the rectangular room, the effect seemed very encouraging. Then, one by one, the constellations were examined and compared to a star atlas.8
A number of errors appeared; two of these amounted to 180 degrees. The positions of twelve stars needed refining. Rejected holes were covered with dark friction tape. Many stars were found to be too bright, or too faint. This was discouraging in view of the precautions taken. Investigation showed that the flashlight bulb, owing to the nature of its filament, was not radiating light of uniform brilliancy in all directions, and that a point source of light was desirable. Various bulbs were tried and it was determined that a 6.2 volt 5‑cell flashlight bulb was most satisfactory, and the globe was reworked to compensate for the non‑uniformity of this bulb's radiation. Accordingly, holes that provided star images which were too faint, were enlarged to proper size. Holes found to be too large were covered by friction tape and pierced by a tapered needle to omit the appropriate amount of light. The optional properties of the pin‑hole became evident as the fainter stars at large angles from the direction of the filament tended to appear as very small images of the filament. This problem has gone unsolved, but has not rendered the projector useless.
In the early projections it was noticed that the star images were all of a single white color, whereas out‑of‑doors many stars appear somewhat red. An exaggerated reddening of certain stars was accomplished by fixing a red transparent paper over their respective holes. The nebulae of Orion and Andromeda were reproduced by fixing a clear cellulose tape over small holes in their direction, diffusing the light in a realistic manner. The star cluster known as the Pleiades required six very small holes, very close together, and was accomplished by drilling a large hole in the globe and masking this by black paper in which the small holes were needled. Approximately sixty man‑hours of work were required to bring the projector head to satisfactory completion.
Design and Construction of the Projector Mounting
A planetarium projector mounting must provide for the apparent rotation of the sky and be adjustable for various latitudes. It was first planned that a hand‑driven mounting be contrived from simple pipe fittings. The details of this mounting were never worked out but it as believed that a small pipe axis could be attached to the to the projector head by means of a flange and that wires could be run through this axis to provide electricity to a flashlight bulb within the globe. In another planetarium‑building project this method could possibly be successfully developed. However, Mr. Harold Ludden was confident that a more finished mounting could be obtained and made inquiries in that regard. He reported to the writer that two men, Mr. Walter Cunningham, a machinist, and Mr. Earl Walters, an electrician, would, together, make an efficient motor‑driven projector mounting for a modest fee if certain materials were supplied. The writer then agreed to purchase the motor and transformer required and to pay the modest fee. Mr. Harold Ludden continued to act in liaison, conferring with these contractors on the required functions of such a mounting. The problem arose as to which direction the axis should rotate. The globe, as a terrestrial model, should rotate from west to east.
However, it was pointed out in conversation with Mr. Ludden that for planetarium purposes the globe should be made to turn the opposite, way, effecting the apparent east to west drift of the stars. In Another conversation the size of the adapter flange for the projector head was established. This size was held to a minimal value consistent with strength, so as to interfere as little as possible with the projection of stars in the southern hemisphere. In still another conference Mr. Ludden was informed of the type of bulb for which the projector‑globe had been adapted, and consequently the type socket required. A later conference resulted in the addition of two rheostats to control the brightness of the stars and the speed of their rotation. The rheostats were donated by Mr. Richard Fritache. Contracting for the projector mounting saved much time and energy which could be applied towards the solution of other planetarium problems and assured a better product than had at first been planned.
It is believed that a satisfactory mounting could have been otherwise achieved but educational values were not ultimately defeated in taking advantage of the outside help. The mounting was delivered complete with an adapter ring which was fixed to the projector head by means of four bolts. Large washers were placed on the bolts to prevent tearing of the cardboard globe. Thus the projector was completed by simply attaching the globe as one would put on a lampshade (see figs. 1 and 2).
The Design and Construction of Planetarium Dome
Mr. Richard Fritsche had volunteered to investigate the problem of providing a hemispherical screen for the projector. He considered fabricating such a dome with paper and aluminum clothes‑line wire and had found the source and cost of such materials. But he was alert for alternative and better solutions of the problem and sought the advice of a former student at the Canton division, Mr. John Paulson of Justus, Ohio, who had entered the business of fabricating astronomical observatory domes. Mr. Fritsche then reported to the writer that Mr. Paul Paulson had available a $ 150, twelve foot diameter, all‑aluminum, hemispherical dome, which was originally intended for the top of a silo. Its surface was rippled to add structural strength and there were wide grooves where each adjacent pair of the nineteen sections were joined. The irregular surface, the small size, and the cost of this dome, were discouraging. however, Mr. Fritsche felt that it should be given further consideration.
As the conversation proceeded, the proposition of using this
dome appeared more feasible. First, if a larger dome was considered, a room could not be found large enough to hold it. Mr. Fritsche suggested that the inner surface might be covered with a paper to provide a smooth screen. It seemed possible that Mr. Paulson might be willing to rent this dome and thus we might have its use at low cost. It was decided To contact Mr. Paulson again.
At a second group meeting, late in October, Mr. Paulson was present and had with him a section of the aluminum dome. An experiment was conducted with this to determine if the complete dome would be satisfactory. By means of the same punched cardboard and flashlight used at the first meeting, star images were projected on and made to move across the aluminum section. The results surprised everyone present. The rippled surface of the aluminum caused negligible distortion and, in fact, contributed somewhat to a realistic twinkling of the star images. The low reflectivity of the aluminum was criticized and Mr. Fritsche suggested that it be painted a flat white. A white paper held against the aluminum section confirmed that the star images would appear considerably brighter if this was done. Attention was next directed to the large grooves by which adjacent sections were joined. These were intolerable gaps in the otherwise usable surface. The writer suggested that these might be filled by thin area of plywood, wedged in tight. Mr. Fritsche countered with the simpler and better suggestion that they be covered by a wide white masking tape which he knew to be commercially available. It was also pointed out that the aluminum dome would be fire‑proof whereas the only alternative solution yet suggested was to use a paper‑covered skeleton of wire. Mr. Paulson was then asked if he would set a rental price for the use of the dome His offer to rent the dome for the remainder of the academic year for fifteen dollars was accepted. The problem of transporting the dome from Justus, Ohio was to be solved by the group. Mr. Stanley Spring then volunteered to use his car and trailer for all transportation necessary in completing the planetarium project. The informal meeting then adjourned.
Accordingly, that week the dome rental was requisitioned from the student activities fund and Mr. Spring and Mr. Ludden brought the dome, in sections, to the Union Building. Through individual contact it was arranged that the members of the project group assist in a trial erection of the dome on a Thursday afternoon, November 3. The dome was set up out‑of‑doors and carefully examined and measured. The need for a supporting ring around the bottom edge was evident. fortunately Mr. Paulson made a surprise visit at this time and agreed to purchase and furnish such a ring at no extra rental charge. The dome was then disassembled and its sections taken to the basement of the Union Building For painting and storage. In a few days Mr. Fritsche submitted calculations and a recommendation that the following materials be obtained: three quarts of flat white paint, two quarts of paint thinner, three one‑hundred yard rolls of two‑inch wide masking tape, four yellow pine boards one and one‑quarter inches square and eight feet long, thirty feet of sash cord, four sash pulleys, twelve clothesline hooks, twelve four‑inch corner braces, six dozen number five three‑quarter‑inch screws, four one‑quarter by two and one‑inch carriage bolts, and eight one‑quarter inch washers. These items, with the exception of the boards, were requisitioned from the student activities fund. The Writer was able to obtain the boards without cost.
Mr. Theodus Cook, another student of physical science, became interested in the project at this point and asked if he could participate.
After consultation with the writer and Mr. Fritsche he agreed to help paint and erect the dome. Together these two students applied two coats of flat white paint to the inner surface of each of the nineteen aluminum sections, working in a basement room at the Union Building. The painting was accomplished in six work sessions.
The problem of finding a location in which to erect the dome began to assume importance. Various rooms at the union building were measured and rejected. The writer then presented the problem to Mr. C. M. Schindler, Director of the Canton Division. Mr. Schindler displayed interest in the project but explained the impossibility of either setting aside one of the class rooms for planetarium use or renting additional high school space. The possibility of making the dome portable was discussed but this was soon rejected as being extremely impracticable. The writer stated that he believed the dome could be permanently installed in a class‑room in such way as to interfere very little with other classes held in that room. Mr. Schindler then suggested that the room in which the physical science classes held be used for the planetarium. This seems particularly desirable, provided the dimensions of the room made the installation possible. Accordingly this room was measured and the data carefully reviewed. A scale drawing showed that the dome would fit between the overhead beam and chandeliers, and that its lower rim would be six feet, six inches from the floor, allowing free movement for everyone throughout the classroom. Mr. Schindler then granted approval for the installation. Thursday, November 24, was set as the date for the installation work. The classroom was freed for the use of the group after 2 P. M. Mr. Spring and Mr. Fritsche delivered the painted dome sections and hardware materials from the Union Building at this hour, and the writer brought the necessary tools. Other project workers arrived to assist as their own class schedules permitted. First, the dome sections were joined and bolted ( see fig. 8 ). This was done with great efficiency and without marring the painted surfaces as a result of the experience gained in the trial erection three weeks prior. By 6 P. M. the dome was assembled and reinforced by the iron ring about its lower edge. The same evening four wood uprights were raised at quadrant points about the dome, in such positions as to interfere least with traffic in the aisles and the view of the blackboards. These uprights were held vertical by corner braces at their bases, reinforced by an inconspicuous bolt into the adjacent desk. A sash pulley was secured at the top of each of the uprights, through which sashcord was threaded. One end of the sashcord was tied to the iron ring at the lower edge of the dome, the other was tied in a loop and drawn over a large hook screwed in the upright. A second and similar hook further up along the upright permitted a lowering of the dome to the eye level of the audience for the demonstration. But this adjustment required the coordinated effort of four people and was later abandoned as experience showed there was little distortion by leaving the dome in the higher position, and raising the projector instead. The latter arrangement made it possible for one man to operate the planetarium and also resulted in better ventilation.
The installation work continued until almost midnight. The workers were then rewarded by witnessing the first demonstration of the planetarium. The other essential apparatus, the projector and its mounting. had been completed earlier. The group was enthusiastic about the results. Mr. Schindler telephone the writer during the evening to advise that some sort of announcement be prepared for classes meeting in that room the next day. He anticipated that other students might react unfavorably to the great change wrought in a conventional classroom and thought that an early statement of its purpose might improve its reception Accordingly a statement was prepared, including a promise that an opportunity for them to view a planetarium demonstration would be later arranged. The statement also carried a warning that everyone use care in moving about the room and not to exert sudden great force upon the structural members until further reinforcement could be made. The group regarded the installation, made according to design, as having too small a margin of safety. The total weight of the dome, about 120 pounds, was distributed at about 30 pounds per upright. Because of the angularity and undetermined strength of the sashcords, the vibration in the system, the loss of strength due to holes in the wood, they felt that structural failure might occur if any part of the system were subjected to sudden shock. All concerned were agreed that the dome supports should be reinforced at the earliest possible moment. The next day, Friday, November 25, the installation was inspected hourly by the writer to determine whether any change toward instability was taking place. Students were asked not to sit directly beneath the rim of the dome as a precaution against injury. The writer conferred with Mr. L. A. Legory, Assistant Director of the Canton Division, regarding the requisition of iron pipe and pipe fittings with which to strengthen the support of the dome. It also was Mr. Legory's opinion that the installation should possess a large margin of safety and he felt that the additional expenditure of activity fund money for this purpose was entirely justified. Various members of the project group were then consulted regarding the design of the reinforcement. Measurements were made and a list of needed materials was compiled. The writer then secured these materials on a university account and brought them to the classroom. Mr. Cook and Mr. Totten erected the four new iron pipe supports within an hour and thus rendered the installation permanently safe by the second day in which classes met beneath the dome (see figs. 4 and 5).
Following a plan suggested by one of the students at the first group meeting, the writer conferred with Mrs. Florence Lewis, Instructor of Art at the Canton Division, regarding the production of a black paper silhouette suggestive of a skyline and to be fixed to the lower inside rim of the planetarium dome. Mrs. Lewis agreed to supervise the designing and making of this skyline effect if the planetarium group would be responsible for attaching it to the dome. The silhouette was to be approximately 40 feet in length, corresponding to the circumference of the twelve foot diameter dome, and was to vary between 6 and 10 inches in height.
Mrs. Lewis then secured the voluntary services of two of her students, Miss Mary Sabato and Miss Marilyn Colaner, and purchased the necessary black paper with money provided by student members of the project group. Within a few days the silhouette was completed and delivered to the writer. Meanwhile Mr. Toten brought in his recommendations on the design and lighting effects. His plan, resulting from experiments he had made at home, called for the installation of a red Christmas tree bulb behind the silhouette at the east and west points of the dome's rim. A small block of wood was to hold the silhouette, by thumb tack, about one inch from the dome's surface at each of these points and provide a mounting for the bulb's socket. The dome was to be wired externally for these lights, the wires terminating in a three‑plug outlet. A three‑wire cable from a rheostat on the operator's instrument panel was to feed controlled current into one or the other of the two bulbs. The cable was to be removed from the dome between demonstrations. Such a plan provided a red glow of variable intensity in either east or west directions, simulating the rising or setting sun. The plan was well made and was approved without modification. Mr. Totten purchased the cable wire and plugs with money provided by student members of the group. The blocks and small sockets were provided by the writer and the rheostat was given by Mr. Fritsche. Mr. Totten brought his own tools and made the electrical installation, working alone one evening. By accident, he found that by removing lines of red pigment from the Christmas tree bulbs beautiful rays as of the rising or setting sun appeared (see figs, 6 and 7).
After the blocks were in place it was possible to attach the silhouette and this was done the following afternoon. The work of adding this skyline effect was done by Mr. Zartman, Mr. Shackle, Mr. Spring and Mr. Fritsche, of the project group, assisted by another interested student, Miss Donna Foote.
THE DESIGN AND CONSTRUCTION
OF AUXILIARY PROJECTORS
From the very first, the problems of reproducing the sun, moon, and planets, which wander among the constellations, pressed for solution. A short‑sighted solution would have been to drill new holes of corresponding size in the constellation projector wherever desired and to cover these holes with tape when no longer needed. In time the constellation projector would have been riddled with such holes and would have been divided into two hemispheres by the plane of the ecliptic. It was suggested that a cylindrical projector be added to the main axis of the mounting and that this consist of a cardboard box, like these in which certain oat cereals are sold. This projector was to be provided with a separate source of light. Holes along the edge of this box would then project the sun, moon, and planets. Such a box could be replaced at intervals with comparatively little work. The writer experimented with such a projector in his home and found the smaller radius of the projector required a smaller bulb filament than was obtainable. If a larger disc was used there would be unavoidable interference with the constellation projector and some stars would be lost in a shadow. The smallness of the planetarium dome required that the distance between the projectors be minimized to prevent noticeable distortion. The writer here had occasion to demonstrate to the students that the planes of great circles intersect at the center of the sphere.
As a result of these considerations, the writer searched for a new solution to the problem. It seemed to him that the drift of the sun, moon and planets was as important to convey as any of their instantaneous positions, and as this would require skillful control, it would be controlled best by the hand of the operator. His hand could be readily placed and moved to minimize distortion and shadow, and thus effects could be coordinated with his lecture. Thus the writer came to the decision to provide hand‑held auxiliary projectors. It required little thought to design and make these projectors. The writer secured small cardboard tubes, used as cores on which oilcloth is rolled, from a downtown store. In these he clipped flashlights of the pen size. Various diaphragms were made from soft‑drink bottle caps (saved, with foresight, from an interlude at one of the groups work sessions) corresponding to the various phases of the moon and the magnitudes of the planets. The edge of a piece of friction tape and the curved edge of a thumb tack superimposed over round hole created the illusions of the quarter and crescent moon. The sun itself required no diaphragm, and was dim enough to permit the simultaneous projection of the background stars, ‑ a very desirable feature in demonstrating the shift of the sun due to the earth's motion in space. Eclipses were made possible by skillful application of an opaque cover moved over the end of either the sun or moon projector‑tube.
From this work emerged the design of the optical pointer, by which the operator could focus attention on any particular celestial object. An arrow‑shaped hole was cut in another bottle cap, and another tube and clip‑type flashlight was obtained. Considerable care in the filing of the bottle cap was required to produce a neat arrow on the sky (see fig. 8). This pointer was indispensable in all the subsequent planetarium demonstrations. This feature made the planetarium demonstration superior to an out‑of‑door night session in which there is often difficulty in pointing out objects. A goose‑neck desk lamp was fitted with a large reflector and a 25‑watt blue bulb, wrapped in a mimeograph stencil. This was connected to an outlet on the projector base through a dimmer switch. The operator could then control the intensity of the blue sky overhead by simply pulling a chain. It was important to adjust the reflector so that no direct light fell upon the audience. The black silhouette skyline deadened this pale light, as it also did the star images, at the horizon. Additions
The first demonstrations of the planetarium, during the week of December 1, 1949, were for the physical science students and faculty members. While the programs were well received, certain improvements were indicated. A steel work table, with casters, owned by the University, was placed in service to make the projector portable (see fig 9). As this table was about twelve inches too low, a box was constructed to raise the projector to about the level of the bottom edge of the dome. This box was designed to include storage space for various items needed by the operator and was wired to furnish a dim light. The light was entirely shielded from the audience and the hemispherical screen. This light proved invaluable at times when the operator found it necessary to refer to notes or technical and numerical data not committed to memory, such as the ephemerides of planetary bodies9, or to fine auxiliary projector tubes.
Improved images from the auxiliary projector tubes were obtained after taping the small flashlights to provide a smaller exit for the light. It was found possible to project conventional slides on the hemispherical screen. University equipment included a film strip of photographs taken at Mt. Wilson Observatory10, together with a small film strip projector, and these were often used following the regular planetarium demonstration to show the advantage of the telescope over the naked eye in exploring space. Time did not
usually permit projection of more than a choice few of the photographs, but these served to stimulate interest, as evidenced by the flood of questions from the audience ( see fig. 10 ).
Several projector bulbs and 100 flashlights batteries were obtained through the university's activity fund, to assure a supply of these expendable items. During the several months in which the planetarium was used these items were all consumed. On request, the administration procured a small two‑faced sign which could be hung on the classroom door. This sign alternately directed visitors to the planetarium and announced that a demonstration was in progress and not to disturb. The excellent illusion of the night sky which the planetarium afforded was comparable to that obtained elsewhere in the large planetaria and encouraged the writer to extend the similarity by the addition of the customary mood music. Accordingly, the university's record player was pressed into service on occasions other then the regular classroom demonstration, particularly when extra curricular and public groups visited the planetarium. The maximum effect was achieved with the record, "The stairway to the stars" rendered by Dick Liebert on the Wurlitzer organ. This was played either as a prelude to the commentary, while the twilight faded and the stars appeared, or else as a postlude to the lecture while the drifting stars became lost in the flush of dawn. The record player was equipped with a volume control which the operator adjusted to levels appropriate to the expanding mood induced by the illusion. The injection of this form of art into the program definitely enriched the experience of the members of the audience. Not only could they see the stars but could also seem to hear the legendary music of the spheres and feel the sense of infinity and eternity ( see figs. 11 and 12 ).
UTILITY AS AN INSTRUCTIONAL AID
The advantage of the planetarium as an aid in presenting an astronomy unit of study is obvious. Classes meeting in daylight hours can there by become familiar with the changing aspect of the night sky (see appendix B). Furthermore, the sky for any hour of the night, any night of any year, as seen from any point on the earth's surface can be quickly presented. The constellations are easily learned by means of the optical pointer. The operator can coordinate his lecture with the direct experience of the individual. Thus student quickly and easily achieve results which would otherwise require years of observation and study. The effects upon our perspective of the earth's rotation on its axis, of the earth's revolution about the sun ,of the orbital motions of the moon and planets, of travel across the surface of the earth, are made clear in a one‑hour demonstration. The fact that the solar system is organized in almost a single plane is forcibly brought out as planets are observed to drift along the ecliptic. The lecturer may comment upon the historical progress of our knowledge of astronomy; how observations were successively interpreted until Copernicus renounced the geocentric cosmogony. The lecturer may also point out that the planets, including the earth, were doubtless formed by a single process, since otherwise their orbits would be inclined at random angles to one another. In the same hour the student observes the yearly drift of the sun through the twelve constellations of the ecliptic, changing its angular distance from the celestial poles and equator in what is named declination. He sees the effect this has upon the noon altitude of the sun, the hours of daylight, and the seasonal warmth. Other techniques and observations can be introduced, such as determining time or geographic location from observations of the celestial bodies, and the daily eastward drift of the moon with its consequent delayed rising and setting and change in phase. And, by no means the least important, the concept can be introduced of the earth's physical insignificance in the galaxy of stars. The operator can strive to bring out the sense of infinite depth in what seems a spherical surface. This is best done by calling attention to the varied distances of stars which appear together in the sky. Demonstrations of this nature were given in all of the writer's classes in "Introduction to the Physical Sciences 162," in accordance with the first purpose of the planetarium project. But the utility of the planetarium was not confined to the physical science courses. On occasion it served as an instructional aid for related units in other courses as follows: On April 5, a class in solid geometry studying the sphere, Mr. E. T. Stapleford, instructor.
On April 12, a class in geography studying the earth as a planet, Mr. James A. Rinfer, instructor.
On April 17, a class in children's literature studying mythology, Mrs. Virginia Sullinger, instructor. The following extra‑curricular groups also made visits to the planetarium in after school hours: The Dramatic Club sponsored by Mr. Michael Dubets. The French Club sponsored by Dr. Kether Grant. The Future Teachers of America sponsored by Mrs. Helen Blue. The German Club sponsored by Dr. Esther Grant. The Pre‑engineering Club sponsored by Mr. A. A. Benedict. While the demonstration had little relation to the purposes of the Dramatic Club, the French or German Clubs, it nevertheless proved interesting to the members and was of definite cultural value. The Pre‑ engineering Club and the Future Teachers of America group regarded the planetarium visit as having a direct relation to their purposes, enriching their experiences, and integrating their previous knowledge of the universe.
For each of these demonstrations arrangements were made in advance. Soon after the planetarium was completed an invitation was extended to all faculty members by Mr. C. M. Schindler, Director of the Canton Division, to visit the planetarium and to determine whether their respective classes or extra‑curricular groups might benefit in witnessing a demonstration. As a result, the writer held conferences with each of the instructors named, in which the time and nature of each of the programs were discussed. The decisions reached were set forth in a memorandum by the writer. From this memorandum, outlines were developed which later served the writer in his capacity as both operator and lecturer, as key‑word reminders of concepts which were considered to be of interest to the group, and which promised transfer of training. For example, in preparation for the program for the solid gemetry class, Mr. Stapleford and the writer developed the following outline:
Time of demonstration: 3 p. m. Wednesday, April 5, 1950 Class: Mathematics 123; Solid Geometry Instructor: Mr. E. T. Stapleford
I. Earth as a sphere
A. Projector is a model of earth B. Up, down, zenith, nadir 1. In line with earth's radius at observer
2. Line along which gravitation acts
1. Plane tangent to earth at observer 2. Perpendicular to radius at observer 3. Slope in space changes with rotation, travel
D. Rotation of Earth
1. Axis determines poles, equator 2. Terrestrial coordinates
3. Cardinal points of compass 4. Meridian plane.
E. Revolution of Earth 1. Orbit forms plane of ecliptic 2. Inclination of equator and ecliptic (intersecting planes) II. Sky as sphere
A. Dome is a model of sky above horizon B. Ribs of dome form parts of lines C. Area of sphere, hemi sphere, square degrees D. Celestial great circles 1. Celestial equator 2. Ecliptic
3. Galactic equator (Milky Way) 4. Horizon
E. Celestial coordinates
F. Celestial poles
G. Celestial small circles
H. Spherical problems 1. Angular measurement a. Pass around bubble sextant b. Measure latitude by altitude of North Star 2. Transfer of coordinates; building projector 3. Spherical triangle a. Zenith ‑ pole ‑ star b. Utility in navigation 4. Time and the ephemerides III. Other enrichments A. Bright star or big star? 1. Angular diameters depend upon distance 2. Apparent brightness depends upon luminosity and distance 3. Magnitude scale and base B. Distances determined by trigonometry 1. Parallax depends upon base line and distance
2. Various base lines used
C. Sun is volumetric mean proportional between earth and star Betelgeux
D. Two pointer stars in Big Dipper determine line which extended intersects north celestial pole.
E. Eclipses of sun, moon, and stars
1. Shadows of earth and moon from sun are right cones
2. Shadows of moon from star is cylinder F. Planets always seen within zodiac. 1. A zone, 14 degrees wide 2. Limited by great circles each 7 degrees from ecliptic
G. Velocity of stars
1. Radial velocity discovered by spectroscope 2. Proper or transverse velocity measured against celestial sphere 3. Resultant velocity by using Pythagorean theorem
H. Drift of Solar System among stars 1. Discovered by changing perspective 2. Stars moving apart at solar apex 3. Stars closing together 180 degrees from solar apex I. Cause of Moon's phases
These outlines were studied just before the demonstration and were only occasionally consulted in the dim light available during the program. It was not possible to prepare and use a complete script for reading during a planetarium demonstration, since the operator was otherwise occupied with the projector controls. Tape recordings were made of many of the planetarium lectures and any one of these is available for auditioning, through arrangement with the writer. Because of its more general interest, the program given the students of the course, " Children's literature " has been transcribed and edited and is presented in appendix A. This program was a result of plans made in conference by Mrs. Sullinger and the writer.
All concerned were pleasantly surprised at the amount of transfer material available. It is probable that in other situations other transfer possibilities would be discovered and used to advantage.
THE PLANETARIUM IN SCHOOL‑COMMUNITY RELATIONS
The continued existence of higher than secondary education facilities within the city of Canton, Ohio depended upon the outcome of a municipal election held February 28, 1950, for the approval of bonds with which to found and operate Canton University. During this campaign the Canton Division of Kent State University felt the necessity of demonstrating to the public what educational and cultural values might accrue to the community if it were to approve the establishment of the Canton University. Few schools have had greater incentive to convince the public of the value of their work than had the Canton Division of Kent State University in this period. The planetarium was completed about December 1, 1949, approximately three month before the election and was then entirely unrelated. That it might serve the public and achieve favorable recognition for higher education occurred to the administration and to the writer early in the new year. It was decided to invite public school classes and young peoples' groups to visit the planetarium. Accordingly, Mr. Harold S. Vincent, superintendent of public schools, and Mr. Ben F. Ahlschwede, director of elementary education, were invited to witness a planetarium demonstration. Both gentlemen were favorably impressed. Mr. Schindler then arranged a schedule announcing times at which the planetarium room could be made available for public school demonstrations, and this was forwarded to the public school administrators in a letter inviting their groups to arrange with the writer for a demonstration. The invitation was a sincere effort to make a contribution to the community and was not withdrawn after the campaign ended in defeat of the university bond issue on Feb. 28. To inform the general public of the planetarium it was decided to invite a newspaper reporter to one of the early public school demonstrations. This was done, and a feature article describing the project appeared in a Sunday edition. The article was not documentary in accuracy, nevertheless it stimulated much interest in the planetarium and many phone calls were received from teachers and principals for a period of several weeks. Altogether thirty‑two public school groups made field trips to the university to see the planetarium. None was disappointed. A list of the visiting groups follows:
The tenth grade of Lincoln High School, Mr. Bigler, teacher.
The fourth grade of the North Canton School, Miss Biralen, teacher
Two eighth grades of Lehman High School, Miss Shirack, teacher.
The sixth grade of Washington School, on January 20, Mrs. Sheehan, teacher, and Mr. Pettit, student teacher. The fifth grade of Washington School, on January 20, Miss Myers, teacher.
The seventh grade of Belle Stone School, February 7, The sixth grade of Summit School, February 7, Miss Greet, teacher
The fifth grade of Hartford School, February 9, Miss Shaw, teacher
The sixth grade of Belle Stone School, February 9, Miss Allmen, teacher
The fourth grade of Baxter School. February 9, Miss Conrad, teacher, and Mr. Sinden, student teacher. The sixth grade of Hartford School, February 10, Miss Switzgable, teacher.
The tenth grade of the Hartville School, February 14. The eighth grade of Belle Stone School, February 16, Miss Booher, teacher.
The eighth grade of Belle Stone School, February 16, Miss Kendrick, teacher.
The third grade of Belle Stone School, February 17. The fifth grade of Belle Stone School., February 21, Miss Little, teacher.
The fifth grade of Belle Stone School. February 21, Miss Murray, teacher.
The eleventh grade of McKinley High School, February 21, Miss Domer, teacher.
The third grade of Belle Stone School, February 23. The fourth grade of Belle Stone School, February 23. The first grade of Belle Stone School, February 23, Miss Reimer, teacher.
The eighth grade of Allen School, February 28, Mrs. Gravo, teacher.
The eighth grade of Allen School, February 28, Mr. Dowding, principal, and Mr. Ferguson, teacher.
The second grade of Belle Stone School, March 2, Miss Hopkins, teacher.
The sixth grade of Belden School, March 2,
Miss Davis, teacher
The seventh grade of Belle Stone School, March 7,
Mrs. Wright, teacher.
The twelfth grade of McKinley High School, March 9, Miss Galbredth, teacher.
The fourth grade of Garfield School, March 14, Miss Dick, teacher.
The sixth grade of Clarendon School, April 11, Mr. Sharp, student teacher.
The fourth grade of Market School, April 18, Miss Waleska, teacher.
In addition to the above, the following five young people groups attended demonstrations.
The Cleveland Plain Dealer delivery boys of Canton, March 6.
Boy Scout Troop Number Forty‑six of Saint Peter's Catholic Church, Canton, March 7.
The Brownie Girl Scouts of the First Methodist Church, Canton, March 15.
The Brownie Girl Scouts of the First Presbyterian Church, Canton, April 6.
Girl Scout Trop Number Twenty‑five of the Edgefield School, April 18.
These lists give only those demonstrations actually presented. There were some last‑minute cancellations at times of inclement weather but these were always re‑scheduled. The average audience on these occasions was comprised of about thirty persons, the extremes being seventeen and forty‑one. Approximately eleven hundred young people are thus represented in the lists. Each demonstration required about forty minutes for presentation, ten minutes preparation of the projector and classroom and ten minutes to restore the classroom for university use. A study was made of the aspects of the sky on the date of each demonstration. The program for these demonstrations varied with the age level of the group, the evening sky on the particular date, and the questions asked by the group. Otherwise the programs were fairly uniform and always began with a welcome and an introduction describing the apparatus and the illusion they were about to observe. Attention was called to the directions along the horizon and the setting sun in the west. The light faded while organ music was being played, and the stars gradually appeared just as they would appear after twilight on that date. After a few moments of silence the operator began a commentary on the night sky, using the optical pointer to call attention to the more prominent constellations, always including the Big Dipper, the Big Bear, the Little Dipper, the North Star, Orion and his dog, and the prominent planets. The older children were told of the early observers who used their imaginations to create the constellations. Children of all ages were asked if they ever connected dots to form figures. Since this was a common experience, the children quickly understood what was meant by forming figures from the stars. The vast distances and sizes of some of the objects were mentioned. The younger children were asked if they could place a ladder against a star and climb to it. Invariably they said it would require hundreds of years, which the operator corrected to millions of years, amidst a chorus of "ohs." Stars and planets were defined. Red stars were explained as being only red‑hot balls of gas, Whereas most such balls of gas are white‑hot . The projector was then allowed to rotate and the operator announced the hour on that date which corresponded with the appearance of the sky. The visitors were reminded that this change in the appearance of the sky was due to the rotation of the earth. Dawn began with a return of the music, and the stars drifted and faded out of sight. The operator remarked that the stars were there all day long but the sun outshone them.
While the writer questioned the advisability of scheduling a first grade visit to the planetarium he acquiesced upon the insistence of Miss Lena Fowler, Principal of Belle Stone School who was convinced, after seeing the planetarium, that every class in her building should attend. The writer was interested in the experiment and had his own seven‑year‑old daughter attend that particular program. As his daughter had not been given any previous training on the subject, he felt her reaction might be indicative of that of the group. Questioning revealed that she remembered and understood the simplified lecture‑demonstration. As in many other demonstrations, the operator tested this group for rapport by passing the optical pointer to several children, asking them to point out the constellation just discussed. The first graders were able to point out the Big Bear immediately, without further coaching.
The programs ended with a projection of a telescopic view of the moon's surface, where attention was called to the grand canyon and rocky mountains of our nearest neighbor in space. It was remarked that some people satisfy their thirst for travel by studying the moon through their own telescopes from their own backyards, and that many other objects in the sky also prove interesting when viewed by telescope. The groups were invited to ask questions throughout the programs, but most questions were asked toward the end of the demonstrations after their curiosity had been aroused and they felt more at ease. The most frequently asked questions were on the possibilities of visiting the planets, whether people lived elsewhere in the universe, the nature of falling stars, and the cause of the phases of the moon.
On one occasion the writer was convinced the children under‑ stood an astronomical concept better than an adult who was present. One teacher reacted violently to the overwhelming magnitude of the subject and expressed grave doubt as to the desirability of allowing young minds to dwell on this subject. The writer has observed children react favorably to astronomy, and he believes that some adults find difficulty in approaching this subject later in life when some erroneous attitudes have to be unlearned.
Many of the groups supplemented their visit to the planetarium with classroom discussions of their observations. One group presented an astronomy program in a school assembly. One principal reported over‑hearing a fourth grade boy explaining red stars to a seventh grade boy after school hours. The writer received one hundred twenty letters from teachers and children who had attended these demonstrations, thanking him for his time. Some of the very young children drew pictures of the planetarium, and their teachers forwarded those to the writer as evidence of their understanding and interest.
SUMMARY AND EVALUATION
A small planetarium was designed and placed in use at the Canton Division of Kent State University through the efforts of small group of students coordinated by the writer during the fall session, 1949. These students acquired a mastery of the fundamental principles of astronomy and a familiarity with the appearance of the celestial sphere. Each received a core experience in cooperation culminating in personal pride in the successful completion of the project. They found a sustained satisfaction in the hobby interest they developed as shown by the fact that several have since acquired astronomical telescopes. Each has reported on the interest friends have displayed in his hobby. The writer continues to receive requests from these former students to meet with them to discuss astronomy or to provide references from his home library on such subjects as the structure and evolution of the universe, the nature of time, relativity, or the new physics. The members of this group learned that these subjects are all related and soon recognized that an increased understanding in these areas provides a broader perspective on life and a more secure basis for their personal philosophy.
The planetarium was used effectively during the remainder of the academic year in connection with related classroom work, extra curricular interests, and for the benefit of public school children of all grades in the Canton area. Approximately fifteen hundred persons witnessed at least one planetarium demonstration. The planetarium soon became widely known in the community. Apparently each person who witnessed a demonstration described it to others. The local newspaper regarded the planetarium of sufficient public interest to devote several columns to it in one of its Sunday editions. Many requests for demonstrations had to be turned down because the classroom was available for only a few fixed hours in a week and these times were often scheduled more than a month in advance. During its brief existence the planetarium made a substantial contribution to the educational and cultural life of the community. From the many questions which were asked during the demonstrations and from discussions which followed the writer found that much interest in astronomy had been aroused and much information successfully conveyed. There was a surprising number of opportunities for transfer of learning into related fields such as physics, mathematics, geography, navigation, engineering, mythology, history, and philosophy. The writer believes there is warranted an increase in the use of the planetarium as a visual aid in the educational program. This is supported by the fact that the planetarium makes conveniently available to students certain significant observations which would not likely be otherwise made. In any school system where sufficient interest prevails an enterprise such as described herein could be developed and used to advantage. In another planetarium building project there would undoubtedly be variations and improvements. A point source of light should be provided for the projector. A larger and smoother hemispherical screen is recommended. The audience should be seated in concentric circles about the projector and operator. Forced ventilation should be provided. Greater freedom in scheduling times of group visits would increase the utility of the apparatus. The room might better be used exclusively for the planetarium, permitting permanent exhibitions of astronomical models, charts, photographs, instruments, and references.
TRANSCRIPT OF TAPE RECORDING OF AN ENTIRE LECTURE ‑ DEMONSTRATION
Mr. Emmons: For the purpose of the recording, this is April 17, 1950, and this is Mrs. Sullinger's class in English 338. Mrs. Sullinger: The course is called "Children's Literature." Mr. Emmons: Now if everyone is situated so they can see the inner surface of our screen I'll turn out the lights. As students of K. S. U. C. you've known that we have produced a planetarium in this room; we've brought in a farmer's silo, piece by piece, put it together and painted the inside white; we've pasted black paper around the bottom, cut so as to represent the skyline with trees and house, and over here in the west, McKinley's Monument, with the setting sun behind it. Within a minute the twilight will fade, and the stars will come out just as they will be overhead in Canton tonight about 8o'clock. Now there you have the sky as it appears over Canton tonight. Since we are at a latitude not radically different from that of the Biblical lands, we see the sky in much the same way as they did over there some centuries ago. Mrs. Sullinger and I were talking before class about the origin of the constellation names. I believe that these constellations were invented by primitive people as the result of their interest in legends and stories. Take yourself back thousands of years in time to the early people who lived in Babylonia and lands thereabout. Many of those people had occasion to stay outdoors at night. There was no artificial light. You recall the shepherds who watched the stars at night to pass the time. They had no way of entertaining them‑ selves other than to watch the show that you are watching now; the sky overhead. It is not very surprising that they were more interested in the sky than we are today; if they had other diversions they might not have been as interested either. At that time the stars presented quite a challenging problem to them. They didn't understand what they were. There was no science of astronomy then; instead, only the conjectures of astrology. They regarded the stars a part of their environment. They were interested in what they were, and particularly in what they meant for them. They thought that it should be determined whether the stars were friendly, or whether they should be afraid of them. So they watched the stars to gather any clues they might of their nature, and in place of valid answers to their questions, they filled in with their imaginations. We can understand how these people, filled with the legends of their time, began to assemble these stars into apparent groups and to give them the names of their legendary heroes. That is probably how many of these constellations originated. A constellation is a group of stars. The stars of a constellation need not be physically related but just in the same general direction from us. Most every person today knows the Big Dipper in the sky. If you just follow this little arrow over here you can see the seven stars which make up the cup and handle of the Big Dipper. Perhaps when you were a child you played a game of connecting dots, drawing a line from one dot to the next dot to form a figure. If you do that with stars you can make some interesting patterns, and the Big Dipper was invented a longtime ago as such a pattern. Now the stars of the Big Dipper are not the same distance from us; they're not on the surface of the sky but they are great suns at different distances out in that direction in space. If you can be like these primitive people and use your imaginations you can make many patterns in the sky, as they did. One of the most interesting or convincing patterns is that of the Big Bear. How many have heard of the Big Bear? Let's take a count. I'd say that nearly three fourths of the class has heard at one time or another of the Big Bear in the sky. Well, if you were to look in the northeastern section of the sky tonight, rather high up, you could find the Big Bear. Let me point it out for you. The Big Dipper, which you now know, can serve to identify this figure in the sky, for the handle of the Big Dipper is the tail of the Big Bear. These four stars forming the handle of the Big Dipper form the tail of our celestial bear. Now follow the arrow, and notice these stars forming the hind legs and the two hind paws of the bear. These three stars in a triangle form his head and his front legs run down to two front feet in this position. You have to lean backwards now to see him upright. Here is his ear. He has a turned up nose. His back runs across here from the head to the tail. Here are the front legs, front feet, and here are the hind legs and hind feet. How many see it now? We have nearly all the class with us. The Big Bear is just one of the constellations in the sky, and if you look in the same direction tonight at 8 o'clock you can see it for yourself, and you could point it out to others. Use a flashlight with a powerful beam which reflects against the dust in the air and serves as a pointer in the sky. Now there is also a little Bear in the sky. I can't distinguish it myself and therefore I can't show you, but it has some relation to these stars in the Little Dipper. Again, seven stars from a cup and handle. The famous North Star is right at the end of the Little Dipper. The North Star can be found by taking the two pointers of the Big Dipper and allowing them to form a line over to the North Star which is always north of you wherever you travel in the northern hemisphere. The stars of the Little Dipper together with others which are fainter, make up the Little Bear in the sky. There is a story about the celestial bears. Mrs. Sullinger: We have been calling the Big Bear "he" but the ancient people called the Big Bear a "she" and her name was Callisto. Callisto, you know, was one of the loves of Jupiter, one of the many loves of Jupiter, one of the women who kept Juno constantly in a quiver of excitement and jealousy. Now Juno discovered that Jupiter was having an affair with Callisto, and so for punishment of both Callisto and Jupiter she changed Callisto into a bear. She said her beauty which had attracted him in the first place should be gone. And poor Callisto fell down on all fours, and her lovely white hands became hairy paws, and her beautiful soft white body became the hairy body of a bear. And she was condemned to live in the woods as a wild beast and to flee from the hunters. She sometimes almost forgot to flee from hunter, forgetting that she was a bear and not a human as she had been. And one day, after she had been a bear for many years, she saw a beautiful youth approaching through the forest. Recognizing him as her own son, she rose on her hind legs and went to greet him and to enfold him to what we would call a big "bear hug." But the youth, of course, not recognizing his mother, drew a bow and was just going to pierce her heart with an arrow when Jupiter, seeing the predicament she was in, took pity on her and on the son and changed them both into constellations and set them in the sky as a great bear and a little bear. Mr. Emmons: It might be of interest that they are very nearly the same direction. Jupiter must have recognized the closeness of the mother and son to place them in the same portion of the sky so that as the nights and years pass the mother, Callisto, is in protective motion about the son, Arcus, as the sky seems to turn due to our turning Earth. Mrs. Sullinger: There is one part of the story that accounts for that. After Jupiter had placed the two bears in the sky, Juno was more angry than ever, "Because now," she said, "I thought I had vengeance upon my rival, and look what has happened; She is in the heavens, and perhaps some day she will displace me." So she went down to the ocean gods, who were her forebears, and she said to them, " Some‑ thing must be done to stop the arrogance of this woman whom Jupiter has placed in the sky. I want you to promise me that you never allow her to enter your waters." And so the ocean gods promised. And although the other stars set into the ocean, the Great Bear and the Little Bear never set. but revolve constantly about the pole. Mr. Emmons: We have started our projector now. and you can see that very motion. The Big Bear in its position in the sky is changing. We have speeded up the apparent drift of the stars 500 times. You wouldn’t see this rapid change out of doors. But if you watched all night long, the Big Bear would seem to cross over and come down in the northwestern sky. It seems now about five o'clock on an April morning and the Big Bear has comedown in the north‑ western sky feet first, to stand erect on the northern horizon. The Big Bear then rises in the northeast without ever having disappeared. You will notice that the apparent motion is centered about the North Star which sets as a hub of the great wheel of the sky. The reason the North Star acts as such a hub is because the Earth's axis in space is constantly pointed toward that star. Now there are some other constellations that we might consider. We'll stop the projector again to show the sky at eight o'clock this evening. If you'd look in the northwestern sky at that time you would see this figure of six stars outlining a broken chair. Here you see the seat of this chair, and these two stars mark the bottoms of the legs. The back is broken at this point. The constellation of the broken chair was thought to be the throne of the Queen Cassiopeia of Ethiopia. This was the Queen's chair, or the Broken Chair, but is sometimes called an "M" or "W". The King of Ethiopia is beside Cassiopeia.
If you wish to remember this constellation, Cepheus, remember it as a pentagon a child would draw to represent a house. This star marks the top of the house, and these four stars the walls. The daughter of Cepheus is Andromeda, a constellation which consists of long chains of stars. These stars are part of Andromeda. Andromeda was at one time bound in chains. Do you have the story, Mrs. Sullinger? Mrs. Sullinger: Yes. Cassiopeia as a very beautiful woman, and very vain of her beauty and by her vanity she so angered the sea nymphs, who thought they excelled her in beauty, that they sent a horrible monster to ravage the coast that Cepheus, her husband, ruled over. And finally, the inroads of the monster became so great that Cepheus went to the oracle to ask what could be done, and the oracle told him the only thing that would appease the monster was the sacrifice of his daughter, Andromeda. So Andromeda insisted that she be sacrificed, against the will of her father and mother, in order to placate the monster and release the countryside from his ravages. So finally they took her and chained her on the seacoast and withdrew to await his coming. It so happened that Perseus was flying home from another mission that he had been on, carrying with him the head of Medusa, the gorgon, which had the power of turning to stone anything that looked directly at it. And as he flew over the seacoast he saw this beautiful maiden, chained and apparently in terror, so he came down to discover the trouble. No sooner had he landed than here came the monster through the waves, rearing up his ugly head and frightening all the people so that they withdrew even farther. But Perseus, flying towards him, held the Medusa head in front of him and turned him to stone and so released Andromeda, and Andromeda was given to him in marriage. Was there any other character in that group? Mr. Emmons: Perseus was mentioned, and this is the constellation Perseus. You'll notice that Perseus looks like a Y in the sky. Here is one branch of the Y and here is the other, and here is the main trunk of the Y. This is a very interesting constellation too, because one of its stars, Algol, as thought by these primitive people to be the eye of some demon because it changed in brightness from night to night. They thought that the eye was winking at them. It wasn't just the temporary twinkling that most of the stars undergo, but instead it was a very methodical and rhythmic brightening and then dimming of the stars. They did not understand that. Now we know what is going on. There is a dark star moving about this brighter one and at intervals partially eclipses it, cutting off its light from us. But these primitive people, of course, had no such understanding and they accounted for the change of light by assuming Algol marked the eye of a devil. Altogether the constellations Perseus, Andromeda, Cepheus and Cassiopeia form the royal family in the heavens. I suppose your imagination is strenuously taxed. We need not apologize for what these early people believed. These constellations and stories are of interest, if for no other reason, because they have been handed down for thou‑ sands of years. There is a dragon in the sky and it is rather easily seen. It is between the two Dippers. Here is the Big Dipper again. Here is the Little Dipper, as you look northeast. The dragon is a snake‑like monster that winds between the two dippers. Here is the end of the monster's tail, and it winds around the Little Dipper in this fashion and bends back on itself to a head of four stars. This fourth star is just behind the tree; and you cannot see it. If you look for it out of doors tonight I'm sure you'll see it. We don't have the time for all the constellations but in the southwestern sky there are several which we would not want to miss. One of these is the constellation of Orion, the hunter, and the others are in nearly the same direction. This star marks the head of the hunter, and these two stars his shoulders. He has a very vivid belt. I suppose if you look for this constellation out of doors at night you will see his belt first‑ three rather bright stars in a line. His knees are in these positions. There you have Orion, ‑‑head, shoulders, belt and knees. From his belt there hangs a sword‑‑ you can just barely see it. He has an upraised left arm in which he holds a club. He is brandishing this club at the lowered head of Taurus, the bull. Here is the bull. Here is his head and his fiery red eye. Here are his horns, aimed at Orion. Together Orion and Taurus seem to march across the sky as the Earth turns. The stars are not themselves moving. It is our horizon that changes. In twenty‑four hours the horizon turns in a complete circle as the Earth rotates on its axis. On the back of the bull you have this little group of stars known as the seven sisters, or the Pleiades. There is a story about them. The hunter Orion has following him two dogs. The big dog is right here. The eye of the dog is the brightest of all stars, Sirius. This dog has a long snout and a longer neck which runs down to a rather small body. Here is his bright eye. Here is his long nose. Here is his long neck and his small body and legs. There is a smaller dog further east but I've never been able to make it out very satisfactorily This star is the eye of the smaller dog, and this other star also forms a part of it. These and others which are fainter in that direction form a small dog, according to the ancient people, and with the larger dog is following Orion and the bull. Mrs. Sullinger, do you have the story of these constellations? Mrs. Sullingor: Yes. Orion is known as the mighty hunter of the heavens, because he was a mighty hunter on earth, too. One day as he strolled through the forests with his dog Sirius at his heels, he saw seven beautiful maidens. He didn't know it at the time but they were the Pleiades, the daughters of Atlas, the giant who held the sky on his shoulders. And Orion was much attracted by the beautiful girls, and immediately began to run toward them and they, taking fright, ran from him. But he kept pursuing them. And such was his strength and his speed that he overtook them and just as he reached out to catch one, she turned into a pigeon, and all seven of them became pigeons, and fled into the sky, and there the gods took pity on them and changed them into the constellations, the Pleiades. Mr. Emmons: There they are. Mrs. Sullinger: One of them is very faint; she is so faint she can't be seen. Actually you only see six of them ‑ don't you, Mr. Emmons? Mr. Emmons: That's right. Mrs. Sullinger: The seventh one left her place because she didn't want to behold the fall of Troy. There are a number of stories about Orion, but the only one we need to concern ourselves with here is the story of his death. He went on after this encounter with the Pleiades and met Artemis, or Diana, the goddess of the hunt, and who was a maiden, a virgin, who kept herself aloof from men as suitors. But she and Orion became the greatest of friends. And her brother, Apollo, I believe it was, became frightened for fear that she would wed Orion and upset all the tradition that had been established about her virginity and her aloofness from men, and so he knew that he would have to plot some way to get rid of Orion. One day Orion was swimming in the ocean, and his great head was just above the waves, and Artemis and Apollo were at some distance. So Apollo said, "Sister, I know your aim is good, but there are some things impossible to you. For instance, I'm sure you couldn't hit with an arrow that black speck out there on the ocean." And Artemis, to show that of course she could, drew her bow and pierced the black speck which turned out to be the head of Orion, and he was washed to her feet. So great was her grief that he, too, was placed in the heavens as the mighty hunter, with his dog Sirius following him. And he is for‑ ever pursuing the Pleiades, as I think Mr. Emmons will show you. Mr. Emmons: Yes, as the earth rotates from west to east, you will notice the reverse effect in the sky where the motion appears west‑ ward. Along about nine or ten o'clock tonight the Pleiades will set in the northwest, due to the fact this horizon is climbing relative to the background of fixed stars. Now Orion is sinking beneath the horizon his head disappearing last, as the story goes. We have at the time of Orion's setting a new constellation appearing in the east which is of interest to us here, and that is the constellation of the Scorpion. Notice this red star which forms the heart of the Scorpion, and these two stars which outline the little body of the Scorpion, and these three stars which from the ends of his claws. Let's stop the projector as the sky appears overhead tomorrow morning about four or five o'clock. If you were to go out of doors at that time in the south you would see the Scorpion. On summer evenings this constellation will be positioned as it is now, and if you recall the pattern and look for it, you will see it then. The Scorpion is followed in its march across the sky by another constellation, Sagittarius. Sagittarius contains another little dipper, upside down. These four stars which form the cup of this inverted dipper also may be thought of as forming a Swiss hat, and this star which forms the end of that dipper's handle can be thought of as the top star in a bow which is bent. Here's the entire bow of three stars which is being held by this archer wearing a Swiss hat, cocked up at an angle. How there is an arrow across that bow and it's directed at the scorpion. As the time passes, the stars seem to drift as if the archer is pursuing the scorpion and about to shoot it. I think, Mrs. Sullinger, you have the
mythology of those two constellations. Mrs. Sullinger: I don't know the mythology of the scorpion but I can tell you a little bit about the archer. When the archer lived on earth his name was Chiron and he was one of the wisest and best of all the centaurs. The centaurs, you know, are creatures that are half horse and half man. And Chiron, I believe, was the one who educated one of the heroes, Hercules. But at the time that Prometheus stole the fire from the gods, which story you will read in your book, or have read, the gods punished him by fastening him to a rock and letting a vulture eat away a part of his body, the liver, I believe, and every night it was restored and every day the vulture ate again. But this time, Chiron, who was immortal and could not die, had been struck by a poisoned arrow from which he suffered greatly and he bounded through the world in his agony and suffering from this arrow. So he asked the gods for full forgiveness for Prometheus saying that he would be glad to give his life as atonement for the sin of Prometheus in order that he might die. And so he was permitted to die as far as earthly life is concerned, but he was placed in the heavens as Sagittarius, the archer of the heavens. Mr. Emmons: Now Sagittarius is just going down, as our projector show, and that would be seen outdoors later in the summer evening. There are other constellations and as the mythologies of these are not connected I would like to simply point them out quickly and then as time permits the mythology can be given. This little constellation of four stars in the figure of a diamond with a fifth star further south looks like a kite with a tail. The boy scouts know that constellations as job's coffin, and the astronomers through the ages have called it Delphinus, the dolphin. Delphinus also is visible high in the summer evening sky. Another constellation which is of interest is Pegasus, the winged horse. These four stars form one of the largest constellations to be found anywhere in the sky. This is the "great square" of Pegasus, and this star over here is a part of the horse's head. His front legs extend westward at an angle. Still another constellation is the constellation of Hercules, which you would find in the northwestern sky on a summer evening. These four stars form the body of Hercules, and the stars off from each corner form the limbs. Now we would like to hear the mythology for the Dolphin, for Pegasus, and for Hercules, Mrs. Sullinger. Mrs. Sullinger: We don't need to go into details because you will read the story of Arion and the dolphin in your books; how the dolphin saved him from drowning and brought him safely to land; how he charmed him with his music, he riding on the back of the dolphin. There are many ancient paintings and decorations that show the dolphins. The Hercules story is a long, long story, much inter‑ woven with a great many other stories in mythology. The only part we need to be concerned with is this: That Hercules was half a god because Jupiter was his father. Of course Juno was very jealous of his mother, and very jealous of him and plagued him all through life. His death was exceedingly tragic. I like to think of him as the original superman for he accomplished many marvelous deeds. His wife feared that his love would go from her to some other woman and she was offered by an enemy of his ‑‑ through Juno's interception ‑‑ a robe, which if he put it on would assure her of his love. So she gave him the robe and he put it on but it was not any love potion at all; It was imbued with a deadly poison which caused him such agony that he immediately set to work to build his funeral pyre, and when it was built and the wood piled on, he threw himself on it and was consumed. But because he was already part a god, he was given a place in the heavens. Pegasus, the winged horse, plays a part in several legends. There is no legend particularly about him except that by stamping his foot he created the fountain which is called Hippocrene
. I believe he himself came from the drops of blood from Medusa's head. He was always associated with the Muses. Hippocrene because the fountain of the Muses. Schiller, the German poet, we are told, tells the story of how a peasant once managed to rope him and leap on his back, when the horse immediately became so spirited that he was beyond control and mounted into the heavens with him. I don't know if that's the time he decided to stay in the heavens as a constellation, or not. Mr. Emmons: Let's stop before we go any farther with the constellations for which we have their mythology and point out the Northern Cross. These four stars in line form the major axis and these three from the minor axis of the cross, a well outlined constellation which is high in the summer sky and which about Christmas time every year stands erect on the northwestern horizon in the early evening. Here is the Northern Crown, a little circlet of stars near Hercules. Now let's allow time to pass until one other constellation rises which has a mythology of interest for us. That is the constellation Gemini. It is rising now in the eastern sky. The constellation Gemini consists of two parallel chains of stars. You will notice that Gemini is not far north of Orion. Orion is rising now. We saw it in the west a little earlier and here it is again ‑‑ the belt, the sword, the head, the shoulders, and the knees of Orion. Could you tell us about the twins? Mrs. Sullinger: The twins of the sky are Caster and Pollux who were earth‑born brothers who loved each other so dearly that when one of them was slain in battle the other petitioned the gods to restore him. They weren't able, of course, to restore him and so one story says that the remaining twin, Pollux, begged that he might give his life in place of Castor so that Castor could be restored and that Jupiter allowed one of them to live one day and one the next. But there are other stories that say that Jupiter took pity on them and placed them both together in the fields of the sky, where they could always be happy together. Mr. Emmons: Thank you. Well now our time is almost up. I was wondering whether I could surprise someone with a request to point out one of these constellations. I wonder how well you can remember the patterns. Mr. Cochran, would you mind pointing out the Big Bear for us again? Take the optical pointer. See if you can recall the pattern of the Big Bear in the sky.
Mr. Cochren: Choose the pattern by finding the Big Dipper. Here's the handle to the Big Dipper, or the Bear's tail. Follow the tail around to the cup of the Big Dipper which forms part of the Bear's back, and higher in the sky you come to the Bear's ear, then down to this turned‑ up nose, and then the feet run down over here. Those are his front paws, and back here are his hind legs that bend. It looks more or less like the Bear is running. Mr. Emmons: Yes, thank you. If you look in the northeastern sky in exactly the same relative direction we have here in the dome to‑ night about eight o'clock you can see the Bear for yourself. We haven't made any extra stars here in the planetarium. Every point of light in this planetarium is representative of a real star in space. The stars may appear a little brighter in here than they do out of doors. In the city you contend with lights and haze and if you go out doors tonight maybe the stars will appear only this bright and you'll have to look more intently to see the outlines. But in here, of course, we can brighten them to suit our convenience. Out on the desert and in those regions of the Bible where people invented the constellations the stars did appear quite bright and clear and they were more conscious of them than we ordinarily are. Well, this is the way the sky is overhead at Canton tonight. Are there any questions? Girl Student: Isn't there any folklore about the red stars? I should think they would have thought they were very different. Mrs. Sullinger: Mars is one, isn't he? Mr. Emmons: Well, Mars is a planet which is red, and it rises to‑ night just about eight o'clock in this position. If you look straight east tonight you will see a very red object which is the planet Mars, one of the earth's neighbor worlds in space. There are several other celestial objects that are red that you have seen. They are distant stars, a million times farther than the planet Mars or the sun. They are distant suns in space. A red star is only red hot, while most stars you see are white hot balls of gas. The red stars are relatively cooler, but definitely not cold. A Girl Student: Could it mean that they are either going to get hotter, or they are getting cooler? Mr. Emmons: It could mean either, and we do know in each case which. This star is going to grow brighter and hotter as millions of years elapse. And there are other stars in the sky which are faint red stars known as red dwarfs, which have passed through their life cycle and which are in the process now of burning out as embers. A Girl Student: Then in the Bible times that star in Orion would have been red. Mr. Emmons: It would have been, yes. In the three or four thousand years that have elapsed there haven't been any significant changes in the sky. For example, the stars of the Big Dipper are moving rapidly. This star is speeding this way at the rate of fifty miles a second. That's over a million miles a day. And this other star is moving also; it is moving In the opposite direction at about a million miles every day. But those stars are so very far away in space that in one hundred thou‑ sand years the Big Dipper will just be barely out of shape. Throughout your lifetime these constellations will appear as they do now. If you trouble to learn these patterns today you will know them in your old age. No matter where you go in the world they appear as old friends. There are about fifty. The constellations are of interest especially to children. If you people are going to teach you might trouble to go out of doors and learn these constellations. References on the subject are available in libraries. If you learn these constellations you will have something which the children will appreciate. Now if there are no other questions, I believe we'll conclude. Mrs. Sullinger: Mr. Emmons, I believe we all want to thank you for showing this to us, and I am sure that as we study the mythological characters that have been named here in the heavens, they will take on new meaning and new significance for us. I am sure that children will find especial delight in being able to identify old story friends in the skies. So thank you for what you have done for us this afternoon. Mr. Emmons: You are quite welcome. Our daylight is coming upon us, the stars are fading out, and we'll have a brilliant sunrise in the east to conclude the show. Applause ( While the class was adjourning the operator was asked about the Southern Cross, and if it were visible from Florida. By an adjustment of the projector it was quickly demonstrated that this was possible. A student asked then about learning additional constellations for navigating in the southern hemisphere, and it was brought out that navigation in all parts of the world could be taught more effectively and efficiently in a planetarium.)
1. "Planetarium" Webster's Collegiate Dictionary 5th edition.
2. Marshall, Roy K., "The Morehead Planetarium" Sky and Telescope 8 (August 1949) p. 243.
3. "Museums" World Almanac and Book of Facts for 1947
4. Letter from David m. Ludlum, sales manager, Science Associates, Philadelphia, Pa. May 12, 1949.
5. Science Associates Advertisement, Sky and Telescope 9. (November 1949) p. 14.
6. Calder, William A., "A Homemade Planetarium" Sky and Telescope 8 (May 1949) p. 181.
7. "The Brightest Stars" The Observer's Handbook for 1949 ed/ C.A. Chant (Toronto: University of Toronto Press:1948) p. 64-71.
8. Webb, H.B. Webb's Atlas of the Stars 2nd ed. (lithographed).
9. U.S. Naval Observatory, American Ephemeris and Nautical Almanac, 1950 (Washington Government Printing Office,1948)
10. Mt. Wilson Observatory Filmstrip, Astronomy ("Science Series"; Chicago: Society for Visual Education,1936