METHODS OF COLLECTING AND PHOTOGRAPHING 



87 



in the bottom. Occasionally dense foliage, a bridge or building is 

 so placed as to form a natural screen, within the image of which 

 photography is possible. 



If the surface of the water is rough the photograph may be 

 made through the bottom of a water glass (Fig. 27). The glass 

 (Fig. 28) is a frame of galvanized 

 iron with a bottom of plate glass. 

 The bail of band iron serves to 

 hold the screen (Fig. 27). The 

 glass shown here is two feet square 

 and is supported on legs run 

 through thimbles at the corners 

 and held in place by set screws. 

 That shown in Figure 28 is a 

 foot square and is intended to 

 float. At the left is shown a 

 cover for the bottom of the water 

 glass. This protects the glass 

 during transit. 



The difficulties arising from the 

 rough or reflecting surface of the 

 water may be overcome by placing 

 the camera beneath that surface. 

 For this purpose a reflecting camera 

 is to be preferred, since it permits focusing with the sensitive plate 

 uncovered. Any dealer in photographic goods can supply catalogues 

 of such cameras showing their mechanism. Here it need only be said 

 that the ground glass is placed in the top of the camera and the oper- 

 ator looks at it through a hood extending from the top of the camera. 

 He focuses the full-sized image on the ground glass and while 

 looking exposes the plate by pressing a button at the side of 

 the camera. For use under water such a camera is placed in a 

 water-tight box (Fig. 29), with a plate glass front through which 

 the lens looks. The hood of the camera extends into the pyrami- 

 dal lid of the box and the operator looks into it through a second 

 plate of glass. A milled head, shown on the right of the box, is 

 connected through a water-tight stuffing box with the focusing 



Fig. 27. Water glass supported on legs as used 

 in rough water of a brook. For description see 

 text. (From an original photograph.) 



