434 OUR COMMON ROADS—MURPHY. 
MACADAMIZED ROADS. 
All roadways having a surface of hard, roughly-broken stone 
are generally classed under the above general head. The most 
important of these are the two separate and distinct systems 
introduced by McAdam and Telford. The pavement of the latter 
is well described thus: “The cross-section of the surface should 
be that of a flat elipse, as this shape assists the water to pass 
from the centre towards the sides, without making the sides too 
round and greatly contributes to drying the road, by allowing the 
the action of the sun and air to produce a great degree of eva- 
poration. When the materials are quarry or field stones, the 
hardest part of them should be used, each stone so broken that 
it may in its largest dimensions pass through a ring 2} inches 
in diameter. When the materials consist of gravel, the stones 
only which exceed 14 inches in size should be taken from the 
pits for the use of the middle part of the road, and every gravel 
stone exceeding 2 inches in diameter should be broken.” 
In constructing a new road (Fig. 1) he directs that a gravel | 
foundation should be carefully laid by hand 7 inches deep in the 
middle, and reduced to 3 inches on the sides ; the stones, none of 
~which should exceed 5 inches in breadth on its face, to be set on 
their broadest ends, and the cavities filled with stone chips. For 
a width of 18 feet over the centre of the pavement, six inches of 
broken stone or hard pebbles, not exceeding 24 inches in diam- 
eter, should be laid. The six-feet roadway on each side may be 
made with good clean gravel or small stones, the whole to be 
covered with a coating of small gravel 1 inch in thickness. He 
directed that all such roads should have a total depth of 14 inches 
of firm material in the centre, and 5 inches at the outer edges. 
That all layers of stone should be placed only in wet weather 
and during the winter months. 
Telford subsequently modified his practice, and in the first 
instance spread four inches of stone, broken to 2} inch gauge, 
which was to be worked in by the traffic, all ruts to be raked 
in as formed, till the surface was firm; after which he laid 2 
inches more of similar material, treated ina like manner, and 
