CH. Ill AXLE-ARM 35 



There is some difference of opinion among coach- 

 ing men and builders as to the relative merits of the 

 mail and Collinge axles for coaches. The usual 

 practice is to put Collinge axles on private coaches 

 and mail axles on public coaches. Owing to the 

 absence of the bolt-heads and the presence of the 

 plated cap, the Collinge axle looks the neater and 

 more finished, and with the use that it gets in pri- 

 vate driving, it will run for two or three months 

 without re-oiling. The mail axle is no doubt some- 

 what safer, but the breaking of the axle close to the 

 back of the wheel, even though the wheel could not 

 come off entirely, would, at any speed, probably 

 cause an accident due to the wheel's beino- twisted 

 to pieces. 



The mail axle requires oiling every one or two 

 weeks, which is not only troublesome, but neces- 

 sitates the constant unscrewing and screwing up of 

 the bolts, which wears the threads and ruins them 

 if it is not done with much care. An oil chamber 

 can be made in the end of the axle, as shown in the 

 cut of an improved mail axle in Stratton, p. 454, 

 and in Fig. 1 3 ; but it is difficult to fill this chamber, 

 the only way being to pour the oil into the wheel be- 

 fore putting it on, while the cap of a Collinge axle 

 is readily filled and quickly put on, before the oil 

 can run out. Collinge axle-boxes are usually merely 

 forced into the hub and not otherwise fastened ; 

 consequently they sometimes work out ; this is im- 

 possible with a mail axle and is one of its chief 



