when it could be more speedily, effectually, and re- | two inches, so as to render it quite rough, or like a 
gularly done in the first instance, by hand labour? 
Again observing that when a carriage wheel, or even 
a horse’s foot fell upon a large stone that was imper- 
fectly bedded or fixed in its place, such stone would 
be moved, or perhaps turned over, by which a dis- 
turbance of all the smaller stones around it took 
place, and they became loosened and disturbed, he 
became satisfied that no large stones should be used. 
The leading feature in M‘Adam’s system of road 
making, therefore, is that no large stone, or stone of 
a spherical or rounded form, however small, should 
be introduced into the formation of a road, but that 
the operation of breaking them should be resorted to 
in the first instance, before they were used upon the 
road; thus not only reducing them to small magni- 
tude but likewise producing sharp points and angular 
edges upon them, in order that they might lock into 
each other, and nearly, if not quite, destroy their 
tendency to roll about or give way to pressure; and 
this has been attended with the happiest result, for 
a bed of broken stone of much less thickness than 
the gravel formerly used, is found to consolidate 
sooner, and to produce a much more durable and 
compact surface than could be formerly obtained ; 
besides which, the broken stones preserve the form 
in which they are placed upon the road, while in the 
old plan the rounded pebbles had a constant tendency 
to shift from the middle of the road, which is most 
used, towards the sides, thus requiring the occasional 
use of the hoe and rake for several weeks, to draw 
them to their former places. 
Another objection to the use of rough or unpre- 
pared gravel arises from the various dimensions of 
its component parts. The small and fine stuff has a 
tendency to set to the bottom, while the large stones 
work out to the surface, and occasion inconvenience 
and irregularity, with great additional wear and tear 
to wheel carriages, until they are broken down; 
while in the M‘Adam plan, as all the stones are re- 
ues to nearly the same size, this effect cannot take 
place. 
Mr. M‘Adam also adopted a new system in the 
repair of former roads, although one of his principles 
was that aroad should never be permitted to get out 
of repair, which may be effected for a long period, 
by care and watchfulness. The method of obtaining 
this desirable end is by having single cart loads or 
small heaps of ready broken stone disposed at short 
distances upon convenient places on the waste ground 
at the sides of finished roads,, or wherever they 
would be out of the way of passengers, and keeping 
a single labourer to inspect a certain distance of road, 
who, with a wheelbarrow and shovel could take the 
few stones necessary to fill up a cavity or rut as soon 
as it appeared, from the pile nearest to it, and thus 
by keeping the whole level, none of those concussions 
of heavy loads occurred, that are more hurtful to 
roads than anything else. A road suffers little from 
a heavy load drawn upon it, provided the surface is 
smooth and regular ; but when ruts or holes occur, 
the wheel sinks into these with all the increased mo- 
mentum of the fall, and produces an effect that may 
be compared to that of a prodigiously heavy hammer 
falling upon the spot: and thus the hardest materials 
soon crush and are ground to dust, while no such 
effect occurs on the .road while kept with a smooth 
and even surface, 
Still, however, the materials will wear out and 
give way in time, so as to require renewal, and when- 
ever this has to be done, broken stone alone is to be 
resorted to; but instead of placing it upon the old 
smooth surface, as formerly done, and where a very 
imperfect incorporation took place between the old 
and hard surface and the loose new materials, he 
prepares the former road by picking up its top surface 
with a short and heavy pickaxe to a depth of at least 
newly formed road in appearance, and upon spreading 
the new stone to a depth of three or four inches upon 
it, a complete binding and incorporation takes place 
in a very short time. To this process he therefore 
applied the new name of lifting a road instead of re- 
pairing it, though in fact, the lifting only applies to 
the raising of the old surface to prepare it for proper 
incorporation with the new material. The road 
being repaired, has to be watched as before stated, 
fora few weeks, to fill up any cavities that may 
occur, since it is impossible, either in making a new 
road or repairing an old one, to dispose the materials 
so equably as to ensure that one part shall not sink 
more than another; but when once these inequalities 
have been adjusted, and the whole surface has be- 
come uniformly hard and smooth, it may be left with 
confidence, as deep holes or ruts occur through neg- 
ligence alone. 
It may at first sight appear that the breaking of 
stones is a tedious and expensive process: so it 1s in 
the first instance, but it affords employment to old 
men and children who might not be otherwise em- 
ployed, and the expense is amply repaid by the 
smaller quantity of stone required, and the little re- 
pair necessary to the road when once properly made. 
When first adopted, Mr. M‘Adam used an iron ring 
as a gauge for the size of the stones, and no stone 
was considered to be broken small enough, unless it 
would pass through that ring. Now the stones are 
carted in their rough state to the road side. The 
labourers sit upon the heap, and selecting a large 
stone as an anvil, they break the larger ones upon it 
with a long steel hammer, taking one at a time, and 
throwing them, as broken, to one side. The work 
is paid for by the bushel of broken stone, and this 
being measured in the presence of the surveyor or 
his overseer, if he meets with any stones that the 
breaker cannot take between his teeth, the work is 
considered imperfectly done, and is not paid for until 
the heap has been gone over again. This is a suffi- 
ciently accurate gauge, and operates as a check upon 
the inattention of the workmen. 
After a new road has been formed, or an old one | 
repaired, Mr. M‘Adam recommends the use of a very 
heavy cast iron roller to be drawn by horses over the 
newly laid stone, to render it more speedily solid 
and compact than it otherwise would be. But a 
roller of sufficient weight to do good, isso heavy and 
expensive that it is not always resorted to. Such a 
roller ought to be about six feet long by tour or five 
feet in diameter, and full an inch and a half thick of 
metal, to be effective. 
perfect drainage for every road; saying that if the 
substratum of natural soil is not kept dry and hard, 
we may in vain look for a perfect road, since the 
best materials will be pushed or driven down, and 
will be buried in the natural soil if soft, by every 
passing load, and in their passage downwards they 
raise and protrude a quantity of that soil, about 
equal to their own bulk on each side, which disturbs 
and mixes with the broken stones, and renders them 
unfit for their office, by destroying the foundation 
they should rest upon. Indeed, so essential it is to 
the preservation of a good road that it should be 
kept dry, that the mud or slush remaining on the 
surface of roads after continued rain, ought never to 
be permitted to remain and dry there, but should be 
scraped off and put in heaps at the sides of the road 
to dry. This scraping should be performed by 
wooden hoes, about a yard long, as iron ones draw 
up the stones and produce irregularity. ‘the road 
stuff, when so collected and dried, forms the best 
sand for building mortar, and is in general very good 
for lining furnaces in which great heat is required, 
and also forms excellent foot-paths. 
And lastly, he insists, (as | 
we have done, ) in the absolute necessity of good and | 
