290
lens, and convinced that it was of similar construction,
Charles entered a protest to the Parisian Académie
des sciences [Academy of Sciences] claiming that the
lens was an infringement upon his original, 1834 tele-
scope design. A closer inspection proved that it was of
independent design, consisting of an air-spaced rear
component.
Also in 1842, Charles met Edmund de Valicourt for
the fi rst time. Valicourt, a photographer and technical
writer, would become an important defender of the
Photographe à verres combinés.
Up and until his death in 1859, Charles continued to
make and sell the Photographe à verres combinées. He
also published a number of catalogues and technical
manuals during the period 1841–1854, on an almost an-
nual basis. These provide a wealth of information about
photographic equipment and processes of the period;
however, they were also characterized by a continual
need to justify and defend the primacy of his lens,
whereupon he publishers letters by noted photographers
attesting to their preference for his lens above all others.
During the mid-1840s, Charles also become embroiled
in a bitter dispute with his Parisian rival Lerebours, and
the two sides traded lengthy insults in their respective
publications. Upon his death in 1859, his son Louis-
Marie Arthur Chevalier continued the business, which
ultimately terminated with Arthur’s death in 1872.
Alan Greene
See also: Daguerre, Louis Jacques Mandé; Lenses: 1
(1830–1850); Niépce, Joseph Nicéphore; and Petzval,
Josef Maximilian.
Further Reading
Chevalier, Charles, Mélanges photographiques [Photographic
Miscellany], Paris, [self-published], 1844.
Chevalier, Charles, Guide du photographe [Guide for the Pho-
tographer], Paris, [self-published], 1854.
Chevalier, Arthur, Étude sur la vie et les travaux scientifi ques de
Charles Chevalier [Study of the Life and Scientifi c Works of
Charles Chevalier], Paris, Bonaventure et Ducessois, 1862
Eder, Josef Maria, History of Photography, trans. Edward Eps-
tean, 1945. (Reprint, New York: Dover, 1978)
Farbre, Charles, Traité encyclopédique de phtographie [Ency-
clopedic Treatise on Photography], 4 vols., Paris: Gauthier-
Villars, 1889–1890.
Gernsheim, Helmut, and Allison Gernsheim, L.J.M. Daguerre:
The History of the Diorama and the Daguerreotype, 2d rev.
ed., New York: Dover, 1968.
Kingslake, Rudolf, A History of the Photographic Lens, Boston:
Academic Press, 1989.
Marignier, Jean-Louis, Nicéphore Niépce 1765–1833: L’invention
de la photographie [Nicéphore Niépce 1765–1833: The Inven-
tion of Photography] Paris: Belin, 1999.
Valicourt, E. de, Nouveau manuel complet de photographie sur
métal, sur papier et sur verre [New Complete Manual about
Photography on Metal, Paper, and Glass], 2 vols., Paris:
Librarie Encyclopédique de Roret, 1862.
CHEVREUL, MICHEL-EUGÈNE
(1786–1889)
French scientist/color theorist
In 1806, after studying chemistry at the Collége de
France, Chevreul devoted his interests to organic sub-
stances at the Muséum National d’Histoire Naturelle
Paris. By 1810, he was chosen as an assistant naturalist
in the department of Garden Plants, a position which
led to his appointment as chemistry chair, and a long
affi liation as an instructor and administrator with the
Muséum. He served as director from 1864–1879. His
scientifi c discoveries included the development of mar-
garine and stearine. Chevreul’s fi ndings revolutionized
the production of soap and candles.
As director of dyeing at the Manufacture des Go-
belins in 1824, Chevreul developed his color theories
which were then publicly introduced in The Principles
of Harmony and Contrast of Colors and Their Appli-
cations to the Arts, fi rst published in France in 1839.
His concept, the “law of simultaneous contrast of
colors,” in which complementary colors placed next
to each other on a canvas are seen mixed in the eye
of the observer inspired painters: Eugène Delacroix,
Camille Pissarro, Claude Monet, George Seurat, and
Robert Delaunay.
On October 25, 1847, at the Academy of Science,
Chevreul’s paper, “Considerations on the Reproductions
by M. Niépce de Saint Victor’s Process of Images that
are Engraved, Drawn, or Printed,” encouraged Abel
Niépce, a cousin of Nicéphore Niépce, to work on new
photographic processes and emulsions.
The Art of Living a Hundred Years; Three Interviews
with Monsieur Chevreul...on the Eve of his 101st Year
is considered the fi rst photo interview. On September
5, 1886, Le Journal Illustré published a series of pho-
tographs (taken by Paul Nadar) documenting conver-
sations between his father Nadar and the centenarian
Chevreul. Each picture is captioned with Chevreul’s
witty response to Nadar’s questions on the subject of
being 100.
Margaret DennyCHILD, THOMAS (1841–1898)
British engineer and photographer in China
Thomas Child was born in Shropshire, England in
1841to John (a mechanic) and Elizabeth. By 1851 his
parents had moved to Greenwich in south London. He
married Ellen in the mid 1860’s and went on to work
as a gas engineer with the Chinese Maritime Customs
in Peking, China.
China had only been open to the West since the
early 1860’s and Child was in the second wave of pho-