396 
Roads and Highways : their Histoiy, 
stones, the traction at a walking pace is not more than three- 
fourths of that upon the best Macadamised roads under similar 
circumstances ; at a trotting pace it is equal to it. 
7th. The destruction of the road is in all cases greater, as the 
diameters of the wheels are less, and it is greater by the use of 
carriages without springs than by the use of those with springs. 
These results most satisfactorily demonstrate the fact that the- 
better the roads the less the traction, and the greater the economy 
of labour. 
Repair. 
In treating of the repair of roads, they may be divided into 
two classes, the first being those which have to endure the heavy 
traffic of towns and their immediate neighbourhood ; and the 
second, those subject only to provincial and agricultural traffic. 
The attrition caused by the wheels of the thousands of vehicles 
which pass over our town roads, many of them carrying weights 
of several tons, produces an immense amount of wear and tear, 
and necessitates frequent and expensive repairs. The thickness of 
the material thus converted from the hardest known rocks into 
mud and dust was stated at the inquiry into the state of Bir- 
mingham, before the Inspector of the General Board of Health,, 
at 4 inches over that part of the surface exposed to the most 
wear, and 2 inches over the whole in the course of one season. 
The difficulty of replacing this material, and combining effec- 
tiveness of repair with consideration for the users of the road, 
has been a matter of much discussion. While all admit that 
only the hardest, and at the same time the toughest material 
procurable, should be used, the method of placing this on has 
given rise to a variety of suggestions. The plan ordinarily 
followed of putting on the road a coating of stone from 3 to 
4 inches in thickness, and leaving the horses and vehicles to 
consolidate it, is desirable neither for the road nor the pas- 
sengers. Until the surface is worn down, traction is immensely 
increased, and consequently horse-power wasted. The loose 
stones are a discomfort and annoyance to passengers, and are 
injurious both to the feet of the horses and the springs of the 
carriages. This process fails to produce a hard jind even 
surface, consolidation being effected only by the squeezing 
together of the stones by the wheels of the vehicles, and the 
chipping off or wearing away of their sharp edges. As continual 
raking is necessary to keep the surface level, in the course of 
time every stone becomes submitted to this chipping-process, 
and ultimately the road-material resembles pebbles more than 
angular cubes of stones. The advantage derived from each 
stone fitting against, and being wedged compactly up to its 
