This apparatus is described in almost all treatises on physics. We may
merely recall the fact that it operated by reflection, that is to say,
the two images were seen through the intermedium of two mirrors making
an angle of 45 degrees. The instrument was very cumbersome and not
very practical. Another English physicist, David Brewster, in 1844
devised the stereoscope that we all know; but, what is a curious
thing, he could not succeed in having it constructed in England, where
it was not at first appreciated. It was not till 1850 that he brought
it to Paris, where it was constructed by Mr. Soleil and his son-in-law
Duboscq. Abbot Moigno and the two celebrated opticians succeeded, not
without some difficulty, in having it examined by the _official_
savants; but, at the great exposition of 1851, it was remarked by the
Queen of England, and from this moment Messrs. Soleil & Duboscq
succeeded with difficulty only in satisfying the numerous orders that
came from all parts. As photography permitted of easily making
identical images, but with different perspective, it contributed
greatly to the dissemination of the apparatus.
The stereoscope, such as we know it, presents the inconvenience of
being incapable of being used by but one person at once. Several
inventors have endeavored to render the stereoscopic images visible to
several spectators at the same time. In 1858, Mr. Claudet conceived
the idea of projecting the two stereoscopic images upon ground glass
in superposing them.
Pages:
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132