ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



461 



&c. ; glass tube for aquatic objects, and forceps. In later constructions 

 Culpeper applied the mirror to one of the feet in a line with the optic 

 axis. 



Hilger's Tangent-screw Fine-adjustment. — This fine- adjustment, 

 devised by Mr. A. Hilger, is in principle a direct-action screw, controlled 

 by a worm-wheel and tangent-screw. The mechanism is shown in figs. 99, 

 100, and 101, and it is applied in the middle of the body-tube. 



A is a tangent-screw, actuated by the milled head A', gearing with a 

 worm-wheel collar B B, having an internal thread by which it 'engages 

 the screw C C at the upper end of a tube sliding within the body-tube°D 

 and carrying the objective at the lower end, the metal stop E preventing 



Fig. 100. 



Fig. 99. 



lateral movement. B B is fitted in bearings so as to rotate only. The 

 rotation of A moves BB slowly round, causing C C to travel up or down as 

 required in focusing. 



Beck & Co.'s Microscopes. 



[" Apropos of the statement in the December number, that Zeiss had recently 

 issued his 10,000th Microscope, we learn that Beck & Co., London, have 

 manufactured over 11,000."] 



The Microscope, VII. (1887) p. 93. 



DiPPEL, L. — A. Nachet's grosses Mikroskop No. 1 imd dessen Objectivform. (A. 



Nachet's large Microscope No. 1, and his Objectives.) 

 [Description of the Microscope described in this Journal, 1886, p. 837.] 



Zeitschr. /. Wiss. Mikr., III. (1886) pp. 457-60 (1 %•). 



Dissecting Microscope, how to make a simple. 



[Made out of a crayon box (or a similar one having a sliding lid) with corks, a 

 rod, wire, &c.] 



Engl. Mech., XI.V. (1887) p. 96, from N. Gleaner. 



HouzEAu, J. C. — Microscope et Telescope. 



Bull. Soo. Belg. Micr., XIIl. (1887) pp. 90-110. 



