5* THE A B C OF PHOTO - MICROGRAPHY 



as a whole, with this arrangement. What is 

 to be done? The section is clearly small 

 enough to be wholly embraced by the objec- 

 tive. It must be the higher magnification and 

 narrower field of the ocular that cause the 

 present trouble. What is to be done? There 

 is no lower power objective with the outfit. 

 We must make use of what we have or aban- 

 don the attempt. We are not going to do 

 that, however, until all efforts fail. Perish the 

 thought! We will discard the eyepiece and 

 allow the objective alone to project the image. 

 This was the almost universal practice in for- 

 mer days, and the one used exclusively by Dr. 

 J. J. Woodward, whose work, as a whole, has 

 never been excelled. It will not answer with 

 apochromats, which require the addition of a 

 compensating or projecting ocular to complete 

 their corrections; but the case is different 

 with achromats, which, properly corrected, 

 will give a sharper and flatter field, when used 

 alone for projection, than in combination with 

 the ordinary Huyghenian eyepiece. Spencer's 

 aplanatic oculars, however, work perfectly with 

 them, and should be used by every one. But 

 to return. In order to see the object, after 

 removal of eyepiece, the camera must be 

 brought into action with tube of microscope 



