Glass Photographic Lantern Slides

‘The Origins of Photography in Salisbury, 1839-1913’ exhibition reminded me of a box of 22 glass lantern slides I had stowed away, given to me by a former rector of St Paul’s Church, probably in the late 1960s.

A lantern slide is a glass transparency that is viewed using a slide projector that casts an image onto a wall or other suitable surface. The light source evolved over time from oil lamps through limelight, carbon arc lamps, and finally electric light. Prior to the invention of photography, painted images on glass were projected for entertainment.

The photographic lantern slide was invented during the 1840s by the Philadelphian daguerreotypists, William and Frederick Langenheim, when they  first used a glass plate negative to print onto another sheet of glass, thus creating a transparent positive image that could be projected. These were used well into the 20th century for displaying photographic images for entertainment and educational purposes. They could be mass-produced and were thus easily available and affordable.

Lantern slides were created by placing a dry plate negative directly onto light-sensitive glass, which was dried, fitted with a cover glass and sealed with tape. Sometimes a black and white photographic image was hand-coloured with special inks before covering.

Among my lantern slides were seven of astronomical interest: two of the full Moon, taken at the Lick Observatory1, four of comets taken in 1906 and 1908 and one of the 1889 solar eclipse. The latter was labelled ‘R.A.S. No. 1. 1889 solar eclipse. Pickering’ (Fig 1) and was accompanied by a snippet from ‘The Observatory’, “provided by the NASA Astrophysics Data System”.

Fig 1 1889 solar eclipse

Part of the magazine snippet read,

“American astronomers are to be cordially congratulated on the brilliant success which has attended their efforts to make the most of the late eclipse. It was not a favourable eclipse in many ways; the duration of totality was short, and winter is not the best time for observations; indeed some of the intending observers found it too cold to make the drawings they wished. But the central line was more readily reached than usual; indeed, though no fixed observatory was actually on the line, several were within a comparatively easy distance of it, and the partial phase was visible both at Lick1 and Washington. It is satisfactory to find that the advantages thus offered for bringing to bear larger telescopes than those which have hitherto been selected, on the score of portability, were fully recognised; and for the first time we find a 13-in. telescope used to photograph the corona., Mr W.H. Pickering having taken from Harvard the instrument provided by the Boyden Fund”.

This eclipse was visible across western United States, and central Canada. Partiality was visible across the northern Pacific Ocean including Hawaii, and all of the United States.

William Henry Pickering (Fig.2) was the younger brother of the distinguished astrophysicist E.C. Pickering, and was born in Boston, Massachusetts, on 15 February 1858. He was educated at the Massachusetts Institute of Technology, where his brother had been professor of physics; and both were associated with Harvard University virtually their entire professional lives. Thus both were later directors of Harvard Observatory facilities; Edward serving as the Director of the principle observatory for over four decades and William serving  as the director of several Harvard substation observatories; one in Jamaica, another near Mt. Wilson and another, Boyden Station in Peru.  William was appointed an assistant professor at Harvard observatory in 1887 and set up Harvard’s Boyden Station at Arequipa, Peru in 1891. Around 1900 he led expeditions to Jamaica, and from 1911 he was in charge of a permanent Harvard observing station there. On retiring in 1924 the Jamaica station became Pickering’s private observatory.

Fig 2

William Pickering was a pioneer in dry-plate celestial photography, and the Harvard photographic sky survey was undertaken at his suggestion. He also made extensive visual observations of the planets and their satellites and in 1888 he produced some of the earliest photographs of Mars, using blue-sensitive plates and the 13-inch Boyden refractor telescope2  (Fig 3).

Fig 3. Boyden 13-inch refractor in Arequipa
(from ‘Catchers of the Light – The Forgotten History of the Men and Women Who First Photographed the Havens. Vol. 1 Catching Space’)

He reported “oases” on Mars (1892), and claimed short rotation periods (now known to be incorrect) for Jupiter’s Galilean satellites.

In 1899 Pickering, in a search for possible new satellites of Saturn, had photographic plates taken, on which he discovered Phoebe, and demonstrated that it has a retrograde orbit. Saturn was the first planet known to possess both direct and retrograde satellites.

From 1907 Pickering paid considerable attention to predicting the location of trans-Neptunian planets; and after Pluto was discovered, faint images of it were located on plates taken for him in 1919. Although Percival Lowell is generally accorded greater credit for this discovery, Pickering’s observation was quite independent and more accurate in many respects.In 1924, Pickering came up with a seemingly bizarre and ridiculous idea. He had recorded apparent changes in the albedo of the lunar surface, which he attributed to hoarfrost and vegetation, and suggested that changing shadows on the floor of the crater, Eratosthenes could be swarms of insects or herds of small animals. These ideas, however, are perhaps not quite so fantastic as they first appear; one should recall that as recently as the 1960’s the possibility of lunar life forms was taken sufficiently seriously to require the first Apollo crews returning from the Moon to undergo extensive decontamination and quarantine protocols. Peter Ryan in his book, ‘The Invasion of the Moon 1957-70’ (Penguin, 1969) wrote:

“Recalling the decimation of many primitive or isolated earth communities upon first contact with diseases common to the ‘civilised’ world, NASA had been under pressure from many scientists to take steps to prevent a repetition in the space context”.

I have donated this whole set of lantern slides to the Museum and Volunteer Alan Clarke has informed the Director, Adrian Green, that these slides, together with two other sets of  lantern slides, constitute a collection of international importance.

  1. Lick Observatory.  Lick Observatory is the world’s first permanently occupied mountain-top astronomical observatory, owned and operated by the University of California. It is situated on the summit of Mount Hamilton, near San Jose, California.
  2. Boyden 13-inch refractor telescope. This was constructed in 1888 by Alvan Clark & Sons for Harvard College Observatory. In 1889 it was relocated to Mount Wilson Observatory in California. During its time at Harvard and Mt. Wilson, Pickering used it to take some of the earliest photographs of Mars, and the following year it was moved again to Harvard’s southern station at Arequipa in Peru.