Art of photography : instructions in the art of producing photographic pictures in any color and on any material, for the use of beginners and also of persons who have already attained some proficiency in the art, and of engravers on copper, stone, wood, etc. (1854)
Halleur, G. C. Hermann, Schubert, F. (Franz) · London : J. Weale · leaf 36
21 THE APPAllATUS. at an angle of 45 degrees; at the bottom of the box there is a small iron cup for the mercury. In front, and at one side, there are two apertures, closed with panes of yellow window-glass, through which the image may safely be examined by daylight, to note its progress. If panes… … Fig. 8 shows a mercurial apparatus of a different construction, which is used in North America. This apparatus affords the advantage of a saving of mercury, as in the first place less of that substance is required with it ; and in the second place, the fumes evolved condense on the sloping 'sides…
Photography
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