•ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



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by a separate pair of tubes, and can be brought close up to the con- 

 denser, or pushed forward to allow of tho use of an alum or glycerin 

 tank. A vertical adjustment is provided for the stage platform, so that 

 carriers of varying depths can be accurately centred and levelled with- 

 out the use of packing pieces. A third pair of tubes carries the optical 

 front, fitted with movable slip-up panels for easy exchange of objectives, 

 or Microscope, polariscope, or spectroscope fronts. 



Sanger, Shepherd, & Go's Safe Lights for Dark Room Illumi- 

 nation. — These (fig. 113) are in reality lanterns of japanned tin 

 plate frame, and are adapted for candle, paraffin, or gas. The burner 



Fig. 113. 



can be adjusted from the outside. The glass forms a light-filter ; it is 

 made bj t combining fired stained glasses, and is therefore' somewhat 

 thicker than the usual coloured glass. The filters are made in four 

 tints suitable for plates of different kinds of sensitiveness. 



Miiller's Rotary Slide Carrier. * — Dr. Miiller, of Tubingen, seeks 

 to overcome the difficulties attendant on the usual to-and-fro push 

 carrier for lantern slides. His apparatus consists of a vertical frame 

 of about 38 cm. diameter 1 rotary about a horizontal axis A, and the 

 whole is set on a bearer T which is clamped on to the optical bench. 

 In the frame are four circular perforations (dotted in figs. 114 and 115) 

 of 13*5 cm. diameter, so arranged that their centres pass successively 

 through the optical axis as the frame is rotated, a catch H fitting into 



* Zeitschr. wiss. Mikr.. xvii. (1900) pp. 162-6 (2 figs.). 



2 R 2 



