92 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



sliding iuto the groove of the large mechanical stage after the springs 

 have been withdrawn. The object-stage can be elevated by means of 

 the screwy ; it terminates at the top in a plate, on which tbe specimen 

 to be examined is placed. The Microscope, as shown in the illustra- 

 tion (fig. 5), is fitted with dissecting-stage and rotating-analyser on the 

 sole-plate with cross slides. 



Some of the accessory apparatus used with this Microscope have 

 been described already.* 



Eleizegui, A. — Un nuevo modelo de microscopio para la ensenanza (1 fig). 



Bol. de la R. Soc. espanola de Hist. Nat. Mii. (1908) pp. 442-4. 



[3 Illuminating- and other Apparatus. 



Beck-Gordon Speculum Lamp.f — This lamp (fig. G) is made for 

 use with the incandescent electric light or the incandescent pendent gas 

 mantle. The lamp depends for its action on a polished glass cylinder 



Fig. 6. 



A several inches long, into one end of which light from the lamp B 

 enters. The light so entering is totally reflected along the sides of the 

 cylinder in such a manner that when it leaves the other end it emerges 

 in all directions not exceeding a moderate angle, so that this end becomes 

 a radiant surface, and behaves as if it were a practically homogeneous 

 disk source of light, in order to secure the best " critical " illumination 

 with powers this surface is focused on to the object instead of the actual 



* See this Journal, 1907, p. 615, and 190G, p. 369. 

 t Special Catalogue, 1909, E. and J. Beck, Ltd. 



