16 



The Ohio Journal of Science [Vol. XVI, No. 1, 



Note 2 — Cross Section of the Sphere Turning Rest. 



m m 



c 



I 



J 



Fig. 7 



In Fig. 7 is .shown a cross section of the sphere turning rest further illustrated 

 in Fig. 4. In machining this the following suggestions should be followed. The 

 piece M should be cast with a lug projecting from the face PQ to chuck it by and 

 all the turning done at one chucking. It should be made a close fit to R and bolted 

 tight against DG and ED' with the bolts S3 and 84, clearance being given along the 

 line HF. To compensate for ware the face DG and ED' can be releaved from 

 time to time with a file. The base N, should be planed along AB, where it fastens 

 to the cross slide of the carriage, then bolted to a face plate of the lathe and 

 finished, care being used to leave the setting of the compound rest unchanged 

 between machining the faces CD and CD' of the pieces M and N. The dove 

 tail on R should be first planed and then this bolted to a face plate and the boss 

 GHFE and the faces KG and EL turned at one setting. If these directions are 

 followed almost no hand work will be needed. W is a brass worm wheel held by 

 screws not shown and J is the sliding tool post clamped at X with the tool at K'. 



