608 



SUMMARY OF CUEEENT EESEAECHES EELATING TO 



thus further insuring uniformity of thickness in the sections. The 

 object-clamp-supporting socket is raised or lowered by a vertical feed 



>.' 



Pig. 4i. 



screw with fine micrometer thread, having a crank at the bottom for 

 independent movement. This screw is firmly held in double nut 



