A Universal Microtome. 



291. 



Fig. 4. 



is found by trial the knife can be re-set at the same 

 graduations on the divided head have been noted. 



angle 



if the 



Other Details of the Desigx. 



A well-designed instrument should work well when worn or 

 damaged, and it should be robust and have few or no delicate 

 parts requiring careful handling. We believe that the new instru- 

 ment fulfils these conditions. It is as robust as the Kocking 

 Microtome, and will stand rough treatment equally well ; it will 

 cut good sections after long use, or even when slightly damaged. 

 The principle of geometrical design has been largely used in the 

 moving parts, so that no unnecessary constraint is given to them 

 and shake is automatically eliminated. The nut on the micrometer 

 screw is an exception ; it is always pressed in one direction and 

 there can be no shake. The clamping devices for the knife holder 

 and the knife itself are not geometric, but there is no movement 

 when these parts are clamped, and we believe that it is best not to 

 make them geometric. 



The other places where movement takes place and where the 



u 2 



