Astronomical Lantern Slides
Three early models of the solar system
Introduction
The Magic Lantern is the forerunner of the modern slide projector. It has a long and complicated history and, like lots of fascinating inventions, many people were involved in its development. No one can say for sure who invented the Magic Lantern. It is part of the marvelous world of optical projection and stands alongside the Camera Obscura, Shadow Shows and the Magic Mirror. Like them the Magic Lantern has been used to educate, entertain and mystify audiences for hundreds of years.
The association of the magic lantern and astronomy goes back to the very earliest time in the history of the lantern. The development of optics in the sixteenth and seventeenth century had the same dramatic impact on astronomy as it did on the magic lantern. Christian Huygens, widely credited with the invention of the lantern, is also a well-known figure in the optical development of the telescope and eyepieces. Today, a Huygens lens is one of the most popular configurations of telescope eyepiece optics.
Through the period from Huygens to the beginning of the 19th century astronomical slides were hand crafted and hand painted, each set being something of a “one off”. The earliest slides I am aware of are part of the Werner Nekes collection . He has several long, narrow mahogany slides consisting of multiple openings covered with paper, the paper features cut-outs of the major stars from some of the better-known Northern constellations. The size of the cut outs relate to the brightness of each star. Werner dates these to circa 1800. He also possesses a pulley and handle slide featuring a brass disk pierced with many holes to represent the major Northern Hemisphere constellations. Turn the handle and the entire heavens revolve around the celestial North Pole, simulating the movements of the stars through the course of one night.
In the last quarter of the eighteenth century, astronomical lecturers were familiar figures. Many were devout men attempting to persuade audiences in the existence of God, others hoped to amaze or amuse, providing spectacle and entertainment. Some of them constructed and operated substantial mechanical displays used while touring and exhibited in theatres and larger entertainment venues. Occasionally they were so unwieldy that a permanent place of exhibition was required. The general content of all lectures was somewhat similar, representing an outline of the astronomical knowledge of the time, couched in non-technical language. Occasionally the lecturer added particular points he wished to emphasize such as probable causes of the great flood or other biblical events.
One of the better-known figures was Adam Walker (1731-1821). From 1776 onwards, he (or his sons William and Deane) toured the UK and occasionally Europe with his ‘Grand Transparent Orrery’ also known as the Eidouranion (from the Greek – ‘form of the heavens’). Details of Walker’s equipment are sparse but one illustration exists. It shows a display apparently using a mix of painted scenery and some form of back projection. A Mr Greene was offering the same “Eidouranion” lecture at Mr Stelle’s Hotel, City of Washington in 1801, claiming he was a former student of Walker’s.
Deane Walker Lecturing at the Royal Opera House in the Strand. 1817
Early Development
Somewhere from within these lectures its possible the earliest slide storylines and images evolved. Additionally, it is probable the showman’s complex equipment inspired early rack work astronomical lantern slides, the manufacturers attempting to reproduce the effects that audiences found so appealing. The mechanisms devised to explain the movements of planets and other phenomena translated into subtle mechanical devices for the magic lantern. Astronomical magic lantern slides frequently show some of the most intricate mechanical effects.
Adam Walker mentioned in 1799 that the magic lantern would be suitable to demonstrate astronomical movements. The book on his lecture also describes several astronomical phenomena he illustrated with the Eidouranion that resemble the earliest effects seen in rack work astronomical slides. In 1824, a Mr Rogers was lecturing in Bath, England using a ‘New Transparent Orrery” supplementing them with sets of transparencies of the sun, moon, planets and nebula painted by a Mr D’Arcy ‘from original drawings by Dr Herschel’. He also offered views with ‘a newly invented grand transparent Microscope’ .
In 1825, a John Wallis delivered popular lectures on astronomy at the Assembly Rooms, Cateaton Street, London, illustrated by ‘an original apparatus devised and constructed by his own hands….including an extensive mechanism and numerous brilliant transparencies. ’ . At the London Institution, Finsbury Circus between 1827 and 1845 he delivered “astronomical discourses’ elucidated by transparent and moving paintings” . Through the 1830’s many lecturers were advertising ‘transparent paintings or transparent moving scenery on their handbills. John Ramage of Aberdeen, Scotland also mentioned showing “fifty splendid transparencies’ .
Following Dr. William Herschel’s discovery of the planet Uranus in 1787 there had been a widespread increase of public interest in astronomy and the movements of the heavens. All these popular lecturers found ready audiences. In most places, the night sky was a familiar sight to most people, with even city dwellers having some rudimentary knowledge in the days before streetlights. In the country, most people knew their basic way around the night sky and understood the phases and movements of the moon. Many evening events were organized around full moon in the hope it would provide extra light for people to make their way home. Astronomy played a more important role in everyday life in the 19th Century, than it does today.
Commercial Production
In 1825, R. Ebsworth (Mathematical, Optical and Astronomical Instrument Maker, 68 Fleet Street, London) produced a set of astronomical magic lantern slides together with a collection of lecture notes. In the Introduction, Ebsworth complained about current lantern practice, “that so ingenious an Optical Instrument as the Magic Lantern should be almost exclusively devoted to the exhibition of subjects that are extremely trifling, and in some instances absolutely nonsensical. To obviate this evil I have prepared a new series of Astronomical Diagrams, with Telescopic views of the planets, displaying the various phenomena of the science in a manner at once pleasing and demonstrative.”
Through the same period, aside from the widespread impact of the introduction of limelight illumination, the major development in the magic lantern was the introduction of copper plate sliders by Philip Carpenter in London. His first set of slides, offered around 1823 was of zoological subjects. Then, sometime in the mid 1820’s he offered a set of astronomical slides. Consisting of eight strip slides (each with three or four images), one slip slide showing eclipses of the sun and a lever slide to demonstrate the rotundity of the earth, the set covered all the basic principles demonstrated by the popular lecturers discussed above. The complete set made up “A Compendium of Astronomy” and the accompanying reading states on its title page “A Series of Diagrams exhibited by the improved Phantasmagoria Lantern’. Although of good quality the images do not show the superb detail and artistic handwork that later distinguished Carpenter and Westley slides. Ebsworth’s lecture matches the sequence of Carpenter’s astronomical slides. It is possible that they developed the same sequence independently but more likely one followed the other's storyline.
‘A Compendium of Astronomy’ - Philip Carpenter’s Copper Plate Sliders circa 1825-30
By 1838, Carpenter and Westley were producing mahogany framed slides in the familiar 4” x 7” format and by 1849 they were offering the ‘Compendium of Astronomy’ set in that format consisting of 32 slides. They were also advertising their sets of rack work “Astronomical Diagrams” in a set of 10 with at least three additional slides available and further sets on Chinese and Arabic Astronomy.
Newton Astronomical Slide Set circa 1850
From roughly the same period, slide sets were available from Newton and Co. They followed a very similar lecture format to the Carpenter and Westley slides, as did their standard set of 10 rack work slides. Today, no one knows if Carpenter and Westley or Newton & Co were the first to produce the rack work set or even a third party. However, each slide (from either manufacturer) shows a degree of ingenuity in its workings and one slide showing the movement of all the planets in the solar system and another showing the orbit of a comet around the sun are particularly complex.
Detail of the Solar System rack work slide
Le Verrier discovered the planet Neptune in 1848. A rack work solar system slide with seven planets dates before this discovery, eight planets (as in the illustration) indicates a date of manufacture after 1848. Astronomical history has many well-defined dates, depending on the information shown on a slide it may be possible to estimate its earliest or latest probable manufacturing date. In addition, most of the information shown in astronomical slides is still valid today. Many of them beautifully illustrate concepts more clearly than descriptions in modern books on the subject.
The phases of Venus, one of the principal astronomical events used to prove that the earth orbits the sun. From a Carpenter and Westley slide.
A Typical Early Astronomy Lantern Lecture
First slide to show the “Figure of the Earth”
The slide set started with a discussion of the figure of the earth. A flavour of the style of the reading can be gained from the text to accompany this first slide:
“Had the surface of the ocean been a level or plain as represented in this diagram, a vessel proceeding out to sea, if viewed from the land would merely appear to increase or diminish in magnitude, according to her distance from the observer, but the whole of her figure would be visible as far as the power of the eye or the telescope could reach. This, however, is not the case when the progress of the ship is minutely observed; for as the vessel recedes her hull first disappears, then her rigging, and last of all her top mast – as though she were sinking into the water. And also, a vessel in approaching an observer would seem to rise out of the water as she advanced towards him. These are appearances which could not take place if the surface of the water were a level or plain. But they arise from its rotundity.”
The second slide would be a mechanical slide. It showed a fixed earth with a ship on a second glass disc attached to a lever handle. Raising and lowering the handle would show the ship disappearing and appearing over the horizon. Again the two observers are illustrated and the shape of the earth (or its rotundity) could be explained.
Second slide to show the “Rotundity of the Earth”
The next few slides would show the different theories on the model of the solar system. The first model was normally the earth centered Ptolemaic model, followed by the Tycho Brahe sun/earth combined model and then Copernicus' sun centered model. The narrative describes this as the “Copernican or Newton model”, explaining that although Copernicus proposed the model, Newton and his mathematics proved it to be correct.
The Copernican or Newton Model of the Solar System
The movement of the earth around the sun and the sun’s annual progress through the constellations of the zodiac, the movement of the moon around the earth and the earth’s rotation on its axis are then explained. There is also a slide showing the size of the earth’s shadow to demonstrate the relative sizes of the sun and earth. Rackwork mechanical slides would demonstrate these phenomena with on screen motion.
The Earth’s annual motion around the sun, showing the sun moving through the constellations of the zodiac. By turning a handle on the side of this slide, the earth appears to rotate around the sun
Slides would follow showing the surface of the sun and its sunspots, the sun with total and partial eclipses, causes of the phases of moon and examples of its appearance at each phase plus a slide showing lunar eclipses. The major surface features on the moon were quite accurately detailed. Slides would illustrate the major planets. Descriptions of the phases of Venus would be followed by a rackwork slide showing the causes of forward and backward motion of the planets. Slides of comets would show the orbit of Biela’s comet, the Great Comet of 1680 and an eccentric motion rackwork slide of a comet showing the tail growing and receding as it orbited close to the sun. Biela’s comet was popular as during its brief life in the 1830’s it remained within the orbit of Saturn and made several passes in quick succession around the sun before breaking up. The Great Comet of 1680 inspired Edmund Halley to investigate comets and the next comet of 1682 became known as Halley’s Comet.
There is then a series of mathematical slides discussing the causes of twilight, the earth’s elliptical orbit around the sun and the causes of stellar parallax. It’s surprising to see a lecture start with the proposition that the earth is round and 20 slides later be showing the concept of elliptical orbits and gravitational attraction.
Slide showing the elliptical Orbit of the Earth by C&W
There follows a series of slides showing a sample of the major constellations. All sets contained the Great Bear and Orion but whole slide sets of the major constellations were available. Carpenter and Westley also produced constellation slides with two glass plates. One glass would show the major stars and the second the mythical constellation figure. By sliding the two plates apart/together it was possible to see just the stars or the stars with their attendant figure outlined.
The final slide recommended by both Carpenter and Westley and Newton & Co was an Orrery slide showing the movement of the planets around the sun. The slide consisted of a series of geared wheels, one for each planet, turned by a threaded handle. The gearing allowed the planets to rotate at a simulation of their respective rotational periods.
Mechanical slide showing the movements of the major planets around the sun
Many other slides were produced by the major manufacturers and could be added to the lecture. Carpenter and Westley produced mechanical slides showing the rotation of the major constellations around the north celestial pole and the south celestial pole. A mechanical slide to demonstrate the causes of the tides was available. Slides were produced showing the major satellites of Jupiter orbiting the planet. Several types of mechanical slides were developed to show the sudden appearance of the corona during a total solar eclipse including complex mechanisms with diaphragms to allow the suns atmosphere (corona) to appear instantaneously. I have seen a mechanical slide designed to show shooting stars using a dark rotating disk with a single bright flash. A slide of stars in the sky would be shown on screen with this slide being superimposed - a rare example of an astronomy slide for use with a biunial lantern. There were also mechanical slides of aurora showing shimmering light effects. Other slides showed atmospheric effects such as mock suns (sundogs) and the effect of looming - the appearance above the horizon of a distant object that would normally be hidden below it, caused by unusually large terrestrial refraction due to a thermal inversion. Several slides of nebulae were available, nearly all based on drawings from Lord Rosse’s telescope at Birr in Ireland.
Specialist Slides
Communicating astronomical concepts continually gave manufacturers opportunity to develop complex and intricate slide designs. One example is a brass and glass device measuring 4” by 7”. It shows the “black drop effect” observed during a Transit of Venus (when the planet passes across the face of the sun). Transits of Venus are rare astronomical events and only occurred twice during the nineteenth century, in 1874 and 1882. As the trailing edge of the planet moves away from the edge of the Sun or the leading edge moves against the edge of the Sun its circular outline appears to ‘bleed’ into the edge of the sun. It is a well-known phenomenon and many papers have appeared to explain the subject. The slide has a complex winding mechanism that pulls a glass disk diagonally across the body. On the moving glass disk is a small dark spot to represent the planet Venus. There is a fixed orange glass disk representing the sun. As you wind the ivory handle, Venus’ disk appears at the edge of the slide and moves onto the solar disk. Then as the training edge of Venus reaches the edge of the Sun the “black drop effect” appears, with Venus apparently ‘bleeding’ into the edge of the sun. Suddenly, the planet appears to ‘jump’ away from the edge and appears as a circular disk again.
Transit of Venus mechanical slide
The transit of Venus in 1874 was widely publicised and it is probable the slide dates to that time. Worldwide, astronomers prepared to observe the event and many observatories developed elaborate devices to train observers on how to time the event and what to expect when seeing the black drop effect. I do not know if the purpose of this slide was for public audiences or training astronomers.
Many of the hand painted slides from the middle of the nineteenth century are beautiful works of art. Most astronomical texts of the time only featured black and white line engravings, lantern slides gave the opportunity to show the wonderful colours seen in the Universe, and with animation.
Diagram to explain how the position of nearby stars moves against the background of more distant stars when seen from different places on earth and at different times of the year. The phenomenon (known as parallax) is the cornerstone of early calculations of the distances to stars. From a Newton & Co slide.
The constellation of Orion. Astronomical lantern slide illustration at its best. From a C&W slide.
Astronomy slides come in almost every conceivable size and format. However, I have never ever seen slides in any of the formats for a child’s lantern. I suspect they do exist and would be interested to hear from anyone possessing examples. There are also examples of slides with replaceable centers although the maker is currently unknown.
A wide variety of slide formats and sizes, all showing Solar Eclipses
I never cease to be amazed at the popularity and worldwide use of astronomical slides. There are slide collections in the archives of most major world observatories. Sets of astronomical slides are in the collections of many museums around the world from Chicago, USA to Liverpool, England to Dunedin, New Zealand. Many collectors of lantern slides have examples of one or more astronomical rack work slides.
Humorous astronomical slides also exist, especially in slipping slides. The slide below shows a somewhat comical looking astronomer whose view a cat suddenly interrupts. It is an unexpected effect. A clown bursting out of a globe of the earth is another common slide.
The astronomer & the cat slipping slide
Impact of Photography
The invention of photography in 1839 did not immediately influence astronomy slides. For many years, photographic processes were too insensitive for quality astronomical photographic images. However, in common with all lantern slides the inevitable move to the smaller format, photographic slides occurred – 3.25” x 3.25” in the UK and 3.25” x 4” in North America. Coloured images were either hand painting or used chromolithographs. Coloured photographic lantern slides are virtually unknown. Astronomers were never interested in colour photography until the invention of digital imaging. Rather than take colour photographic images they would shoot in black and white through colour filters. This eliminated the major drawback of obtaining true colour images when very long exposure times are used.
The astronomers end of the Yerkes Observatory 40 inch refracting telescope – the largest refractor in the world. From a Keystone & Co slide.
Reading for a Keystone & Co slide set “The Origins of The Universe”. Unit S-5 in their General Science Sets. Produced in the 1950’s.
During the second half of the nineteenth century, developments in astronomical science began to change our knowledge dramatically and the subjects shown on slides became more complex and involved. Although manufacturers still made slides showing the common elements, they began to produce technical teaching sets.
Newton by Newton!
Portrait of Sir Isaac Newton from a Newton & Co slide set.
By 1900, York & Co of London were producing a 300-slide set. They described it as “by far the most comprehensive set yet published and is specially adapted to meet the requirements of Public Lecturers and teachers of Science. It embraces the chief results of Modern Astronomical Study and also the applications of Spectrum Analysis to the physical constitution of the sun and stars’.
The New Manufacturers
Towards the end of the nineteenth century, most companies that produced scientific instruments were marketing astronomical slides. Many of the World’s major observatories began offering slides taken from their most famous photographic images, particularly the Yerkes and Mt Wilson establishments in the USA. The Royal Astronomical Society in London produced lantern slides and many of its members used them for both public lecturing and teaching. By the 1930’s even amateur organisations like the British Astronomical Association were offering slides and had a rental library for the use of members.
A unique lantern slide photograph of the moon.
It was taken by FW Longbottom, an English amateur astronomer on March 23rd 1896. Handwritten on the slide mask are full details of the telescope used, exposure and development details
- All the information required to make it into a serious scientific observation.
The Academic Lecturers
One of the foremost popular lecturers at the end of the 19th Century was Sir Robert Ball, Lowndean Professor of Astronomy at Cambridge. He carefully balanced his professional duties with his public lecture tours as well as several appearances at the Royal Institution, London. He also made three lecture tours of Canada and America. An Edinburgh journalist wrote in 1905 “there is no important town in England, Scotland, Ireland or Wales and no important scientific institution in the country where Sir Robert Ball has not lectured and in most cases lectured often. At a very moderate estimate over one million people have heard him lecture. ” Even allowing for exaggeration, in 1905, this was at the height of his fame and he continued lecturing for a further five years. Almost without exception Sir Robert lectured with a lantern. In one of his notebooks he wrote a brief reminder to himself “beware when lecturing in Manchester. They get bored after 75 minutes.”
By the end of the nineteenth century, the increase in leisure time, desire for self improvement and the rise of local Literary, Philosophical and Scientific Societies made attending astronomy lectures a very popular public pastime. Many well respected astronomers gave public lectures. However, Ball was one of the last great astronomy academic popularisers who specialised in lecturing. The technical advances in astronomy in the early 20th century lead to such high levels of specialisation that few professional people became famous for their public lecturing on the subject. Lantern manufacturing began to decline and by the 1920’s astronomy slides were mainly produced for use in academic institutions or by astronomical societies. Later slide sets assume a reasonable level of prior knowledge from the audience.
Sir Robert Ball giving an Astronomical Lecture at the Royal Institution in 1889
Ultimately, the production of slides declined to one or two companies. To my knowledge, Newton & Co produced the last astronomy slides in the UK sometime in the 1930’s or early 1940’s. Universities and Observatories produced their own slides for teaching and lecturing purposes through the 1950’s – many made by photographing book illustrations. The Keystone View Company was still producing teaching sets of lantern slides into the 1950’s and possibly the early 1960’s.
Samples of slides produced in house by a Dutch University for teaching students.
The Last Production
However, the most recent slides in my collection come from an unexpected source. I have a series of 63 3¼” x 4” format slides produced by NASA mainly dated between 1962 and 1968. A few are early designs for the Space Shuttle with eight-dated March 1972 - NASA published final designs for the Shuttle Orbiter that month. These slides would have been part of the public information released to explain the final design configuration. As you can see from the illustration, NASA had its own slide masks. On the reverse side is a NASA Part Number. Obviously, they produced many slides. Interestingly, the most technically advanced organisation in the world probably produced the last astronomical lantern slides.
1972 NASA Press Release Slide
Conclusion
Astronomical magic lantern slides have been around in quantity at least since the beginning of commercial production. Some of the examples from the first half of the 19th century show great ingenuity in the mechanical designs used to take complex phenomena and produce fascinating on screen effects. Public lectures on astronomy were very popular in the 19th century and even relatively complex concepts in astronomy (celestial mechanics) were frequently presented. The surviving number of astronomy lantern slides indicates that sets were sold in their hundreds (if not thousands) throughout the century. By the early 1900’s sets of slides were aimed at teaching or lecturing to audiences who already possessed some level of knowledge. Lectures for the public would of necessity use only a subset of the full group. There was a shift from popular lecturers (entertainers) to academics (educators) through the 19th century and developments in magic lantern technology assisted this process. Aside from formal academic teaching, the use of astronomy lantern slides faded along with all other popular uses of the lantern. However, manufacture of teaching sets continued through the 1950’s and NASA produced information slides into the 1970’s
You can read a brief history of the magic lantern here.
All images from lantern slides in the author’s personal collection.
References:
iii An Epitome of Astronomy including an account of the Eidouranion or Transparent Orrery, William Walker, Bungay 1802
v “The Every-Day Book “, William Hone, 1826: 30 – Hone also wrote: “Here is a sure mode of acquiring astronomical knowledge, accompanied by the delightful gratification of witnessing a display of the heavens more bewitching than the mind can conceive.”