238 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



with two cross-walls forming a species of shaft open on top. In the 

 dovetailed grooves set in these shafts are situated the special objective- 



S 



Fig. 44. 



Fig. 45. 



carriers /, in such a manner that the space between the" shafts serves as 

 free room for adjusting the carriers. This adjustment is conveniently 



