ZOOLOGY AND ROTANY, MICROSCOPY, ETC. 



637 



two previously described at the June meeting. It is of ivory, and, 

 though bearing no maker's name, was probably made by Adams about 

 1746. There are seven object glasses, a lens-carrier for opaque work, 



Fig. 140. 



and nine ivory object slides. A light condensing lens is mounted on a 

 brass slide just below the object slide. 



Horizontal Travelling Microscope.*— This instrument (fig. 141) 

 made by the Cambridge Scientific Instrument Company, is for measuring 



Fig. 141. 



small differences of length. A vertical Microscope is fixed to a carriage 

 mounted on a geometric slide and is moved in a horizontal direction 

 by a micrometer screwreading to - l mm. 



* Catalogue Optical Convention, 1905, p. 219, fig. 11. 

 Oct. 18th, 1905 2 U 



