40fi 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



and 60 mm. in a horizontal direction, is fitted, also rack-work Bubstage, 

 and large plane and concave mirrors. 



C. Baker's Student's Microscope* (fig. 52), also on the Continental 

 design, can be provided with either a round or square stage, a sliding 

 substige tube, or a screw-focusing substage capable of being turned 

 aside when not required. This instrument has spiral, rack, coarse, and 

 micrometer-screw fine-adjustments, and is mounted on a steady tripod 

 foot ; it is usually supplied with one eye-piece, two objectives, £ in. and 

 I in., and dust-proof double nose-piece. Incase, with handle, lock, and 

 key. 



(3) Illuminating- and other Apparatus. 



C. Baker's Electric Lampf (fig. 53) consists of an incandescent bull), 

 silvered on the outside except a small window, which is frosted; it is 

 1 thick enamelled, and the brilliant light obtained only proceeds from the 



Pig. 53. 



frosted window. This forms a very comfortable illuminant to work 

 with, as no stray light affects the user's vision. It is mounted on a 

 heavy stand, with adjustment for inclination. 



C. Baker's Portable Battery Lamp J (fig. 54) consists of a small 

 4-volt built in metal cover, with bull's-eye condenser mounted on arm 

 with universal movements, and an upright on circular base, and a two- 

 cell battery. This lamp will burn for twenty hours continuously, and 

 can be readily re-charged without sending to an electrician, at a small 

 cost of sixpence. The light is powerful enough to illuminate a T Vm, 



* C. Baker's Catalogue, 1915, pp. 24-5. 

 t.C. Baker's Catalogue, 1915, p. 52. 

 j-C. Baker's Catalogue, 1915, p. 53 



