Ch. VII] PHOTOGRAPHY WITH A VERTICAL CAMERA 209 



needed for the desired magnification or reduction. For this reason 

 the same device was applied to it as to the original vertical camera 

 of 1879, viz., a rod passing from end to end of the camera, fixed at 

 one end and clamped at the other. When the camera is extended 

 the exact amomit required for the size in a given case the clamp is 

 fixed so that the length of the camera cannot be changed, then the 

 whole camera may be moved for focusing without any danger of 

 varying the magnification. This device saves a great deal of time 

 and keeps one good-natured. In the original camera of 1879, the 

 rod was graduated in centimeters. This of course helps to give the 

 proper extension with the least outlay of trouble. In fig. 126 the ver- 

 tical supporting rod is graduated in centimeters and half centimeters. 



§ 331. Lighting for the vertical camera. — The object should be 

 so arranged that all the details come out with the greatest distinct- 

 ness. As the hght must be largely from the side it is often necessary 

 to put a piece of white blotting paper or cardboard on the side of 

 the specimen opposite the window. Occasionally for Hghting up 

 deep cavities it is a great advantage to use a mirror and reflect sun- 

 light into the cavities for a part of the exposure. 



Great care must be taken in selecting a suitable background so 

 that the specimen will stand out clearly and not be merged into the 

 background. 



When a white background is used, the shadow of the specimen is 

 often very troublesome, and to distinguish the outhne of the object 

 W. E. Rumsey (Canadian Entomologist, 1896, p. 84) hit upon the 

 plan of placing the object on a glass plate and putting the back- 

 ground on a stage below (fig. 126). A background on the 

 lower stage does away with the confusion. If daylight is not 

 available excellent photographs can be obtained with mazda lamps 

 with metalHc or white reflectors to direct the light. It is usually 

 better to employ two portable lamps and arrange them so that the 

 shadows will not be too prominent. 



§ 332. — Photographing embryos, small animals, and organs. — 

 The camera shown in fig. 126 is admirably adapted for this, as the 

 objects, many of them, must be photographed under water, alcohol, 

 or other Uquids. 



