NOTE ON A NEW HAND MICROTOME. 



319 



which is here figured meets all these objections, at the same time 

 supplying a clamp far more efficient than anything which has yet 

 been introduced. 



Fig. 1 gives the general view of the instrument, which, it will 

 be seen, does not depart materially from the common form. At 

 the top it has the usual circular stage serving as a guide for the 

 knife, and at the bottom a micrometer screw, the milled head of 

 which is divided into ten parts, the rotation of the screw through 

 one of these divisions giving an upward movement of ^^ mm. 



Fig. 2. 



Fisf. 3. 



Figs. 2 and 3 show the internal arrangement of the instrument, 

 consisting of three separate parts. A, B, and C, of which B is the 

 object-holder. This part B resembles somewhat . a crayon-holder 

 of large size, with four slits ; and it is so arranged, by means of 

 a cone fitting, that when the object surrounded by the packing 

 of pith has been introduced into its upper end it can be clamped 

 by means of the outer cylinder A being screwed upon B. Such 

 a method of clamping the object, in that it gives equal pressure 

 and support from all sides, is far preferable to the one-sided clamp 

 generally used. 



