. Nature . a time, the water is suddenly turnedon, the fish or other creature heads upto the stream, and a snapshot can betaken in a natural position. For theabove work it is desirable to use areflex camera with a rapid lens of notless than 8-inch focal length. For the photography of compara-tively small and microscopic marineobjects a sp&cial apparatus is neces-sary. I use a portable apparatus withwhich it is possible to take a photo-graph of a specimen in a horizontal orvertical position, by transmitted or re-flected light, and by means of a mirrorto see the object up to the last moment befo
. Nature . a time, the water is suddenly turnedon, the fish or other creature heads upto the stream, and a snapshot can betaken in a natural position. For theabove work it is desirable to use areflex camera with a rapid lens of notless than 8-inch focal length. For the photography of compara-tively small and microscopic marineobjects a sp&cial apparatus is neces-sary. I use a portable apparatus withwhich it is possible to take a photo-graph of a specimen in a horizontal orvertical position, by transmitted or re-flected light, and by means of a mirrorto see the object up to the last moment before expo-sure, so as to ensure a living specimen being photo-graphed in a suitable position. There is also a fixedstage upon which a specimen can be placed in a tankor cell, and a photograph taken of any desired magni-fication without moving the specimen. When photographing from life-size up to 25 mag-nifications I use lenses of 6-inch, 32-inch, and lengths, on a camera having an extension of. Fir,. 2.—Whelk feeding on Crayfish. 36 inches without a microscope. For higher mag-nifications I drop a microscope into the apparatus,and get any desired magnification up to 2600 with aI/12-inch oil immersion. The exceptional length of bellows extension isnecessary in order to obtain a high degree of mag-nification from a lens of comparatively long focus,thus ensuring all parts of the specimen being in focusat the same time. July 7, 1910] NATURE The advantages of such an apparatus at a biologicalstation or on a research boat are obvious, forspecimens taken from the trawl or tow-net can beplaced in suitable tanks or cells by the biologist, and 1 p^g ^ ,ii«i HRm ^^^^Bf. • ■^^ ^.^oadH ^^■^ - *^=^^S^^B B |,v photographed, living, anaesthetised, or dead, by anassistant. Any number of useful records could thus bemade from fresh specimens of any particular photographic purposes it is desirable to obtainperfect living specimens; but the photography of tage be employe
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Keywords: ., bookcentury1800, booksubjectnaturalhistory, booksubjectscience
