THE ROAD. 
merely decreases the velocity of his coach, by increasing 
the quantity of friction. Common sense must likewise 
instruct him, that when two bodies are rubbing against 
each other in opposite directions as the arm of an axle- 
tree and the iron-box of a wheel the smoother these 
bodies can be made, the less, of course, is the friction. 
As economy in the expense of power is one of the chief 
objects of a mechanic, it is not to be wondered at that 
great pains have been taken in the construction of the 
axles and boxes of carriages. To Mr. Collinge are we 
chiefly indebted for his patent cylindrical axletree and 
box, which have stood the test of many years, and given 
universal satisfaction for the silent and steady motion 
they impart to the wheel for their great strength and 
durability and for carrying oil several thousand miles 
without the necessity of replenishing it. They are 
turned upon a lathe, case-hardened, and rendered as 
smooth on the surface as it is possible, in the existing 
state of the art, to render them. But as the expense of 
these boxes is too great for stage-coaches, patents have 
been taken out for others of a less costly nature, which 
answer extremely well, and have long since been in use 
on all the coaches that run from the Bull and Mouth, 
and many others besides. No stage-coach can be safe 
without the patent boxes, as they are termed, but there is 
a prejudice amongst proprietors against them. They 
certainly add to the cost, and also to the weight, of the 
coach ; and by preventing the wheels from escaping any 
obstacle that may present itself the consequence of 
