502 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



of the disk and can be firmly clamped from below. The mean rotation- 

 point of this spherical clamp arrangement lies only very little under the 

 clamp, so that in changing the inclination of the object the height of 



Pig. 50. 



Fig. 51. 



the object is only slightly altered. Blocks of wood or grooved metal 

 disks with their paraffin or celloidin beds can be secured to the clamps, 

 and by the addition of a little more molten matter the object and mean- 



