676 On the Advantage of Employing 



cost about a quarter more than the latter, as they will 

 last at least twice as long, and require much less re- 

 pairing, they will be less expensive in the long run. 



The tires of the new wheels being twice as broad 

 as those of ordinary coach-wheels, they are much less 

 weakened by the holes pierced to receive the nails or 

 iron pins which fasten them to the felloes : they are, 

 consequently, much stronger and less liable to be 

 broken in use. 



As the tires are broad enough to prevent the wheels 

 getting into the spaces between the paving-stones, they 

 will be less worn, and worn more evenly, than the tires 

 of narrow wheels. They will also wear the pavement 

 much less, and do less damage to unpaved roads, and 

 indeed to any sort of road. 



It is only necessary to take care that the axle of 

 these new wheels is straight, or nearly so, that these 

 wheels may roll flat upon the road ; for, without this 

 precaution, the wheel will be impeded in its motion, and 

 the tire will be worn more on one side than on the 

 other. 



Having had a new axle made for my carriage 

 (5 inches longer than the old one), I have given my new 

 wheels an inclination of only three lines, and that 

 seems to me to be enough. 



If, in the case of a carriage provided with ordinary 

 wheels having a good deal of inclination, it is desired 

 to substitute for these wheels others with broad felloes, 

 without changing the axle, it can be done ; but in this 

 case it will be indispensably necessary for the tires of 

 the new wheels to be slightly conical, instead of being 

 cylindrical as they ordinarily are made, and for the 

 felloes to be made of the proper shape to receive them. 



