413 



with 4 teetli ta, just fitting into tlie four teeth ta^ belonging to a 

 siuiiiiar enlargement at the base of the axis a,. This steel axis ri, 

 passes tiirongh a copper case k (soldered to the cover), in which it 



-5- 



-4- 

 -3- 

 -2- 

 -1- 

 -0- 

 -1 — 

 -2- 

 — 3 

 4^ 



^ 



-mi 



;; H' /;ii\\ i i i'i ir ' i i 'liii \. 



JM 



mm 



■vai 



CHJ 



Fig. 3. 



fits exactly, but may be easily rotated. Ronnd k tiiere is a glass 

 cylinder //, closed at the bottom by the india-rnbber-ring r. The 

 axis a, is at the top tightly clasped in a copper tnbe k^, at the 

 bottom of which the hollow metal cylinder c is fastened, and at 

 the top the grooved wheel sn. By the oil in g the axis is closed 



27* 



