APPENDIX (PART II) 



163 



mentary camera, which is moved by the focussing screw of the other in such 

 a way that the plate ready for exposure is maintained in register with it. 

 The attachment of the supplementary camera to the sliding front and the 

 swinging back of the other, permits of niceties of adjustment which could 



Photograph b;/ Messrs Watson <{ Sons. 



FIGURE 255. "The Eton Nature-Study Camera." 



not be obtained if the cameras were arranged one above the other. As the 

 picture in the supplementary camera is smaller than the one in its fellow, 

 there is no necessity to make allowance for the fact that one lens does not 

 absolutely cover the same field as the other. A cheap lens can of course 

 be used in the supplementary camera, which latter can be removed at will 

 when it is not required. 



