4 PHOTOMICROGRAPHY 



will be further loss of time, as either the camera 

 or microscope, or possibly both of them, will have to be 

 undamped and fixed in another position. These difficulties 

 and others may be so easily overcome by the provision of 

 a baseboard or optical bench of some kind that no attempt 

 should be made to take photomicrographs without one, and 

 a baseboard is so easily made by anyone having ordinary 

 proficiency in the use of tools that the first thing to con- 

 sider, after the camera, microscope, and illuminating 

 system are obtained, is how to design one suitable for the 

 apparatus. It must be constructed so that the optical 

 axes of the microscope, lamp, and condensers shall be 

 truly in line and perpendicular to the focussing screen 

 of the camera, and so that any of the pieces of apparatus 

 can be placed in its exact position without loss of time. 

 Above all, it must be so rigid as to prevent vibration as 

 far as possible in any part of the apparatus. Illustrations 

 are given of arrangements we have made ourselves to 

 adapt apparatus already possessed. They have proved 

 adequate, and are offered primarily as an indication of 

 the lines to be pursued. A different camera, microscope, 

 or lamp may involve a different arrangement, but very 

 little ingenuity is necessary to devise one suitable to the 

 materials at hand. 



Illustrations are also given of several cameras on the 

 market, each of which is fitted with an accurately made 

 optical bench. They are not necessarily any more efficient 

 than home-made apparatus, though they may be expected 

 to be much better finished, to work with greater nicety and 

 precision, and all these points become of great importance 

 in difficult work, and add immensely to the ease with which 

 photomicrography is carried out. 



The Camera. A camera specially made for photo- 

 micrography can hardly be described as a necessity, 

 and many workers are content to adapt the one they use 

 for other purposes to microscopical work, or else to fit 



