

IV 



are * edges, generally rectangular in section, but 

 times circular ; they are made of wrought iron or steel, and 

 sd for securing wheels, pulleys, cranks, &c., to shaft*, 



(V 



(V 



'. . \\ : ! . SSftlJ 



haft 111 I i-ut its Imliiini; |MM-T is small, and 



it i, tli, ,!",. .-..: :\ v i ig the key on a 



/I, Hometimec called a yAr/ /.-/ Tli- hol.lim; | M u,. r ,,f this 

 key U inu.-li -r-atr than that of tin- saddle k 

 the wtiJi / y secure and \ .TV common f- 



u|H.n \\h rests is called the 



kry b"> iixl tli- i ..-- in the boss of the wheel or 



lu!lry into which th- k.-y tits is callwl the ; hoth are 



also called by ,//., \S . 1 1 , saddle, 6V . , k kt*ys the key 



jKir.ill'-l to the axis of UK* shaft : but tin- key way is 





