P ROTOGRAPHICAL SECTION PrOCESDINGS. 



1101 



the organized company of capitalists may well afford nicely adjusted 

 and exquisitely working instruments, which are far beyond the reach, 

 or even the hope of many, in whose catalogue of expenses the neces- 

 sary, and often perplexing items connected with the cost of living, 

 must be first and greatest. 



During the last few months I have received several letters of 

 inquiry as to the best method of copying pictures and other objects 

 occupying a flat field. Several of these letters have thus far remained 

 unanswered, save by a simple acknowledgment of their receipt and 

 a promise of further attention at some future time ; and I do not 

 know that they can be better answered than through the photo- 

 graphical section of the Institute, and hy a descriptive sketch of the 

 device which I have had in use several years, on ordinary work, and 

 in fact upon several occasions where adjustments to the j\ ^ of an 

 inch wore required, a nicet}'' far beyond which the apparatus is quite 

 eflicient when properly constructed. It will be readily understood 

 from the sketch and following description : 



A is a plain smooth board of any desired length and breadth, hav- 

 ing a cleat at each end, to prevent warping or splitting, and having 

 a groove, B, plowed in its upper surface, along which the tongue- 

 guide of the sliding board or camera truck, C, can easily move and 

 thus be kept parallel with the base, A. tJpon this truck, C, which 

 rests upon four small wheels, one under each corner (but not shown 

 in the figure), the camera is placed with its front resting against the 

 ledge, D, in which position it may be clasped by a set-screw, though 

 I do not find it necessary to do so. The board or truck, C, may then 

 be made to travel with its load, the camera, forward or back to any 

 desired point ; and its position will be indicated by the index, E, 

 moving over the scale, F, which is divided into tenths and hundreths 



