88 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



instrument, and may be fitted either at the top of the body-tube, or at 

 the lower end, as figured. 



Watson and Sons' Museum Microscope.* — This instrument (fig. 5) 

 has been designed especially for the use of students who may be pur- 

 suing some particular branch of study, or for visitors to museums. It 



I'ig. ;>. 



consists of a dust-proof mahogany-framed glass case, in which the 

 Microscope is fitted. The objects, 12 in number, are mounted upon 

 a disc, which can be rotated from outside the case. The eye-piece of 

 the Microscope also projects out- 

 side the case, and focussing is 

 effected by means of a milled 

 head, actuating a rackwork-and- 

 pinion on the right-hand side of 

 the case. 



Method of Fitting the Stage 

 and Limb of Watson's Van 

 Heurck Microscope.f — In this 

 instrument the contrivance (fig. 0) 

 for connecting the limb, stage, 

 and substage is especially calcu- 

 lated to ensure rigidity of the 

 whole Microscope. The limb A is 

 fitted into the sub-stage bracket- 

 plate D, which is held firmly by 

 screws ; the joint-bolt B goes 

 through the whole — limb and 

 stage - bracket — rendering the 

 limb, stage, and substage as firm as if they were one piece. This stage- 

 bracket C C, instead of being screwed to the front of the limb, as is 

 usually done, is made in a solid casting ; it takes the substage beneath on 

 the plate D, and goes right into the joint at the top of the pillar. The 



* W. Watson & Sons' Catalogue, 1902-3, p. 77. 



t Tom. cit., f p. 61. 



