LOW-POWER WORK 25 



board quite securely to the camera. It should be mentioned a little exactness is here 

 required, so as to make the camera fit well home against the brass end referred to, 

 but it repays the trouble, for if well done the camera should be quite firm and rigid, 

 even though it is secured by this single screw. The other two holes are tapped to take 

 the thumb-screws which attach No. 3 board firmly to No. 2. 



It may be convenient to give the exact dimensions of the apparatus : 



Camera length from end to end . . . . 13 inches. 



Width 53 „ 



Board 2 — Length 13I „ 



Width 53 „ 



Five-eighths of an inch thick, with a thin piece of brass at the end. 



Board 3 — Length 16 inches. 



Width 3i „ 



Thickness ...... 2 „ 



All these three pieces are seen fixed together in Fig. 13, but the camera is not 

 shown fully extended. When all three pieces shown in Fig. 1 1 are firmly fixed, it is 

 easy to see the camera will travel in the slide shown in Fig. 12. This can be made 

 to fit piece 3 in Fig. ] i without any trouble, but the board of which it is made should 

 be constructed of inch stuff, and the guide rails (which are tapped for the thick 

 wooden screws shown black in the drawing) not cut out of too thin material. Ours 

 were made of mahogany i inch wide and i|- inch thick. The length of the board 

 found most convenient was 3 feet, and the width about 8 or 9 inches. Care should 

 also be taken to get a well-seasoned flat piece of timber for this purpose. 



It is very obvious now that if to the end of the railed board, Fig. 12, the object 

 holder (shown at S in Fig. 9) be firmly attached, the whole apparatus can be easily 

 placed on an ordinary studio camera stand and clamped in position in front of the 

 condenser. One important convenience of this arrangement lies in the fact that a 

 great amount of possible shake is thereby lessened, for, even if the camera, lens, or 

 object be jarred the whole piece is thereby shaken in one mass, which does not affect 

 the centreing of the picture or its adjustments; whereas, if the object had been 

 separately supported apart from the camera, any touch to either would immediately 

 have imperilled the focussing of the picture. This little point is well worthy of notice, 

 as it is a help towards getting perfect results, saves time, and reduces failures. 



In taking the photograph, then, the camera can be slid with perfect trueness to and 

 fro, until, in fact, the magnification required is obtained ; and it has only to be clamped 

 by the wood screws passing through the mahogany rails, for all to be complete. 



P 



