98 PEACTICAL TREATISE ON THE MICEOSCOPE. 



provements in the stand of his instruments ; the compound 

 body is now mounted upon a plan somewhat like that of 

 Messrs. Smith and Beck ; it slides up and down in a dove- 

 tailed groove in the arm, but the dove-tail is turned the reverse 

 way ; its extent of motion is much increased, so that the lowest 

 powers may be employed, and two milled heads instead of 

 one, as heretofore, have been adapted to the rack movement. 

 He has also added the moveable stage, represented in fig. 48, and 

 increased the angle of aperture of the two inch, one inch, and half- 

 inch object-glass to the same extent as those of Messrs. Powell, 

 Ross, and Smith, so as to render them capable of being used 

 with the ordinary long compound bodies and eye-pieces of 

 high power. 



Mr. PUlischer has been a manufacturer of microscopes in 

 this metropolis for the last four years ; he supplies three kinds 

 of stands. The first and most complete of these is represented 

 by fig. 49; it consists of a firm tripod of brass, A, similar to 

 that of Mr. Ross, in Plate 1 ; to this are fixed the two curved 

 supports, B B, of a stout plate, capable of being turned on 

 two trunnions, one of which is seen at C. This plate forms 

 the under surface of the stage, I, and to it is firmly fixed the 

 bent arm, D, supporting the compound body, which last slides 

 in a dove-tailed groove, after the plan of Mr. Jackson, and is 

 moved up and down by rack and pinion. There is a draw- 

 tube in the compound body at F, immediately below the eye- 

 piece, G ; the coarse adjustment is made by two large milled 

 heads, one of which is seen at E ; the fine, as seen at H, by a 

 screw acting on the end of a lever, a plan first adopted by 

 Mr. Ross. The stage, I, is on Turrell's plan, but by a con- 

 trivance of Mr. Pillischer's, it is considerably reduced in thick- 

 ness ; the two rectangular movements being effected by 

 turning the milled heads, K L, the latter having a corre- 

 sponding miUed head on the opposite side of the stage. The 

 mirror, M, is of the usual construction, and slides up and 

 down a tube attached to the under surface of the stage-plate. 



A second microscope for students has a foot and uprights, 

 the same as the larger microscopes ; the support for the com- 

 pound body is a bent arm, to which is attached a tube, about 



