ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



647 



view can be designated. It is especially adaptable for class-work, where 

 the teacher wishes to demonstrate to his pupils.* 



Fig. 148. 



Reichert's Goniometer-ocular.f — This (No. 94 in maker's catalogue) 

 is represented in fig. 149, and is intended for the measurement of angles 

 of crystals. 



Fig. 149. 



Reichert's Objective.! — The 8 mm. objective of the Hart apochroinat 

 series has been increased in N. A. from 0*5 to 0'6. There is also a 

 general reduction of prices. Among the achromats there is a new ^ in. 

 water immersion of N.A. 1 ' 10-1 ' 15 : and anions; the semi-achromats a 



new 



TTT 



in. homogeneous immersion of N. A. 1 ' 3. 



(3) Illuminating- and other Apparatus. 



New Easily Legible Micrometer Divisions. § — Gebhardt has, 

 with the help of the Zeiss firm, designed a micrometer with a novel 

 style of graduation to lessen the difficulties felt in the application of 

 the ordinary pattern to uncoloured objects, and to minimise the fatigue 

 frequently experienced in continuous observations. The new ideas are 



* It is noteworthy that this device is due to Quekett. See Quekett on the 

 Microscope, first edition (1848) p. 130, fig. 91.— Ed. 

 + C. Reichert, Vienna, Catalogue, Mikroscope, p. 42. 

 J Tom. cit., pp. 11-12. 

 § Zeitschr. wiss. Mikrosk., xxiv. (1908) pp. 366-9 (2 figs.). 



