OUR COMMON ROADS—MURPHY. 463 
The pressure per inch of width of tire cannot always be taken 
as a fair measure of the load on a road ; a good deal will depend 
upon the sort of road. A strong, hard road, on a good founda- 
tion, will bear a considerable load on narrow tires without 
perceptible damage being produced, while a more yielding road 
will break down, although the pressure per inch of tire is far less. 
The table given applied to McAdam and Telford roads, and 
would not at all apply to the soft or more yielding surfaces of 
roads in Nova Scotia. 
The diameter of the wheels, as influencing the pressure on the 
road, may be left out of account for wheels of common size on 
ordinary road surfaces. 
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