94 



ARRANGEMENT OF APPARATUS, ETC. 



to place a concave, and we believe sometimes a con- 

 vex lens, between the objective and focussing screen, 

 when increased magnification is required. Mr. 

 Woodward was the first to suggest this practice; 

 it is not to be recommended, as the increased mag- 

 nification is more easily obtained by enlarging the 

 negative; besides any combination above the objec- 

 tive impairs the image. It is our firm conviction that 

 nothing has been such an obstacle to the practice of 

 Micro-photography, as the failures consequent on 

 allowing the eyepiece to remain in its usual position. 



We shall now point out a few of the advantages 

 of our own method. 



Any microscope can be fitted with the necessary 

 additions at a trifling cost, the amount depending 

 on what can be done by the possessor himself; in 

 fact, the majority of first-class instruments, already 

 possess these additions. 



The same apparatus answers with every method of 

 illumination, it can be made to assume any position, 

 the use of oblique light is facilitated, and the em- 

 ployment of photography with objects in fluid be- 

 comes possible. 



On account of its portability the several changes 

 are easily made, while the simplicity of its construction 

 prevents the possibility of its getting out of order. 



In the following pages we have adopted the plan 

 of describing a different method of illumination, and 

 arrangement of apparatus with each objective, in 

 order to illustrate the employment of different 



