HF The History of Photography 600pág

Photography by artificial light 427
attraction. At the Photographic Society's exhibition in February I858 the inventor
showed five ambrotypes 'taken at night by artificial light'. 'Hideous portraits, ghastly
and gravelike' commented a critic, but this may have been a prejudiced opinion, for
during the winter of I86o-I no fewer than 30,000 portraits were taken by the light
of the Photogen, 'The Special Wonder of the Age-the Rival of the Sun'. One
photographer claimed to have taken more than sixty portraits in one evening.4 On
dull days Moule used to invite clients to return in the evening so that he could photograph
them by the light of the Photogen.
MAGNESIUM LIGHT
In I859 PROFESSOR ROBERT WILHELM BUNSEN of Heidelberg and (SIR) HENRY
ROSCOE of Manchester, for several years collaborators in photochemical researches,
reported to the Royal Society on the extreme brightness and actinic qualities of
burning magnesium wire and its value as a source of light for photography.5 Their
paper attracted the attention of EDWARD SON STADT of Manchester, who set to work
to produce the metal in a marketable form. He took out patents for methods of
manufacture in I862 and I863 when he founded the Magnesium Metal Company in
Salford. He presented one of the first lumps of the purified metal to Faraday at the
Royal Institution, where the element had been discovered by SIR HUMPHRY DAVY
in I 808. Within a year the company was able to produce thin magnesium wire at a
price of 25. 6d. a foot (255. an ounce) and, later, magnesium in ribbon form, which
the Manchester photographer ALFRED BROTHERS had found more efficient. The firm
also made the first holder for burning the wire.
On 9 February I 864 Professor Roscoe read a paper 'On the use of the light of
magnesium wire as a photographic agent' before the Literary and Philosophical
Society of Manchester, and on 22 February Alfred Brothers took the first portrait
by this new light, the sitter being Roscoe. The wire was burned at a distance of 8 ft.
and the negative was said to be equal to any obtained by sunlight. On 8 March
Roscoe's paper and Brothers's experiment were communicated by Sir David
Brewster to a meeting of the Photographic Society of Scotland in Edinburgh in the
presence of Fox Talbot, and at the conclusion JOHN MOFFAT took a portrait of Brewster
and Talbot with an exposure of 42 seconds.6 On 6 May I 864 Alfred Brothers
photographed Faraday by the new artificial light after a lecture by Roscoe at the
Royal Institution in London.7 The day before, A. Claudet had given a demonstration
before the Society of Arts in London, by photographing a white marble bust of
Prince Albert in 30 seconds.
As the metal was still only produced in small quantities the price remained high ;
it was not until about I865, when the price had fallen to I25. an ounce (silver then
cost only 55. an ounce) that the new light-source became generally available, one of Pl 228
its earliest non-photographic uses being to illuminate the excavation work then in
progress on the Mont Cenis tunnel.
The first subterranean use of magnesium light for photography was demonstrated
by Alfred Brothers when, early in I 864, he took a stereoscopic picture in the Blue
John coalmine in Derbyshire. In May I865 the JACKSON BROTHERS of Oldham, at
the request of the Manchester Geological Society, took four views in the Bradford
Colliery, but owing to the dense smoke from the magnesium wire in the 4 ft-high
tunnel no more could be taken.8
By burning a triple strand of magnesium wire and using his miniature camera (see
chapter 20) the Astronomer Royal for Scotland, c. PIAZZI SMYTH, arrived at almost
instantaneous exposures when photographing the interior of the Great Pyramid in