THE THOMA MICEOTOME 



465 



In- shifted vertically and horizontally by means of the small screw w, 

 and is fastened by means of the milled head, m. By the pinion n it 

 may be displaced over 90, and as great an inclination can be taken 

 in a plane perpendicular to this by the supporting metal frames by 

 means of the pinion p. In this way every desired inclination of the 

 object to the knife can be readily secured. 



Fig. 393 presents the same object-holder, but instead of the 

 cylinder a simple pair of jaws with the screw /// to secure objects of 

 every A-ariety. A. cylinder-holder as in fig. 393 can be placed in 

 these jaAvs from which the benefits of the Neapolitan holder can be 

 secured. But fig. 396 shows a still greater improvement which can be 

 applied to both object-holders, viz. " perpendicular displacement />// 

 means of a co/j "//</ /><///<> governing the height of the mass from 

 which the sections are to be cut. 



The elevator in fig. 393 is supported on one side by the prism P, 

 and 011 the other by tin- rod C: these are joined by the bridge/.. 



FIG. 394. Object-holder movable about two horizontal axes at right angles 



to each other. 



to which a cogged bar is fastened, into Avhich a pinion catches, Avhich 

 is moved by the lever V, allowing a perpendicular displacement ot Hie 

 object of 12 mm. At is the millimetre scale on which the perpen- 

 dicular displacement can be read off by means of the index x. 



An object-holder movable about two horizontal axes situated 

 perpendicularly to each other is seen in fig. 394. These positions 

 are fixed by the milled heads />'. 1> ; < j shows the jaAvs for holding the 

 object, into Avhich, however, cylinders like fig. 39r> may be intro- 

 duced. This object-holder has a perpendicular displacement con- 

 trolled by a screw. The part, K. which supports the chief axis of the 

 jaws, is fitted on to the triangular prism 8/. the louer part of which is 

 furnished Avitli hinges ; on the hinge the screw V moves, which at its 

 upper end lies close to K, and is sustained in this position by the 

 steel plate g, so that K is carried up and down with it. and this 

 movement is read off by a .scale under 8. 



n n 



