AD5 4 OUR COMMON ROADS—MURPHY. 
trees, removing all wood larger than #-inch in diameter, and 
intermixing them with clay to the consistency of adobe, and 
applying the mixture to the depth of from 9 inches to 1 foot, a 
tolerably fair road may be maintained. I have been informed 
that this class of road will wear well for four or five years’ traffic. 
Hemlock tops, wood shavings, straw, or coarse dry grasses might 
be made use of where the spruce or fir could not be had conven- 
iently. These make shifts should not, however, be attempted on 
roads where the traffic is heavy. A well-drained road, with a 
Telford pavement and McAdam covering, is the best we know of 
at present to meet any requirement of heavy traffic. 
SLAG FOR COVERING. 
The slag from the furnaces of the Acadia Iron Mines, London- 
derry, has been very successfully employed for repairing roads in 
the neighbourhood of the Mines, and its employment is being year 
by year extended to quite a distance. The town of Truro has 
made use of it for repairs of the streets, but not with much 
success. The writer is under the impression that it has not had 
a fair trial at Truro. It was made use of in lumps too large, 
when its proper application should be as near as possible to a 
powder or very small pebbly state. It may be excellent for a 
binding material, and should not be denounced without a further 
and better trial. In a paper by the writer, read ‘before the 
Canadian Society of Civil Engineers (pp. 92, 93, vol. 2,Transac- 
tions Canadian Society of Civil Engineers), the result of experi- 
ments on this slag as a mortar was given, and although as a 
mortar or cement it did not behave so successfully as expected, 
still as a road covering it might have large possibilities. The 
barrel of slag supplied from which the briquettes were made, 
showed the silica in a vitrified condition, also fused silicate of 
lime already formed with the alumina burnt to a white dry 
cinder. When there are thousands of tons of this material avail- 
able, and so situated that it can be loaded into the railway cars 
from the embankment, where it is dumped, without the cost of 
repeated removal, we would wish to see it receiving a better and 
fairer trial before its value as a road covering is condemned. 
