ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
737 
right-hand panel, 5 in. from the top, is fixed a large set-screw, which 
works through a slot in the corresponding side of the inner box into a 
Fig. 84. 
Fig. 85. 
nut (fig. 87), so that when the screw is released the inner box may be 
raised or lowered, and when tightened the two boxes are securely 
clamped together and fixed at any elevation. 
(2) Eye-pieces and Objectives. 
New 1/5 Objective.* — Mr. J. Michels states that he possesses a 
1/5 objective of 50° air angle which was constructed for him by Spencer 
and Smith, of Buffalo. The lens has fine definition and is specially 
adapted for work with covers 1/10 in. thick. The writer thinks that a 
lens of this sort, one that can be used in conjunction with a compressor 
having a screw-adjustment at each end, and with a cover-glass 1/10 in. 
thick, will be found very useful to those making biological researches. 
Koristka Semi-Apochromatic 1/15 Objective, f — Herr J. Amann 
gives the results of the tests which he has applied to this objective. 
According to the catalogue of the firm, the composition of the system is 
similar to that of the apochromatic, except that the fluor-spar is replaced 
* Amer. Mon. Micr. Journ., xv. (1894) pp. 156-7. 
f Zeitschr. f. wiss. Micr., xi. (1894) pp. 145-8. 
