363 



ROADS. 



value will be proportioned to their solidity and du- 

 rability, it is essential that he should understand 

 the absolute and relative strength of materials, the 

 resistance they offer to friction and shocks, the 

 changes which they undergo from exposure to the 

 . atmosphere, and to the more ordinary chemical 

 agents, such as fire, salt water, &c., as well as the 

 time and labour required in preparing them for the 

 purposes of building. 



Boads, — It has been well remarked, " that the 

 expense of constructing a new road, or of main 

 taining an old one in good order, greatly depends 

 upon the kind of ground under it, upon the facility 

 with which proper stone may be obtained for it, and 

 upon the stability of the various cuts which it may 

 be found necessary to make in the rocks, is well 

 known. It is not, however, so well known, that 

 these circumstances depend upon the geological 

 structure of a country, and that a knowledge of this 

 structure would enai3le those who possess it to de- 

 termine whether one line of a new road would be 

 more costly than another ; whether, when it be- 

 comes a question to patch up an old line of road or 

 construct a new one, the one or the other will be 

 ultimately found least expensive ; and that some 

 kinds of stone should be employed upon roads in 

 preference to others, when several kinds can read- 

 ily be obtained." An attention to these particu- 

 lars, however unimportant they may appear to 

 some, would save in this country many thousands 

 of dollars annually. Those who have travelled 

 much, and seen how our roads are constructed and 

 repaired; how, in some places, a soft, perishable 

 stone is brought from a distance, when a far better 

 material is close at hand ; how slatestone and 

 graywacke are often beaten up, and used either for 

 the foundations or repairs of common or even Mac- 

 adamized roads, which are soon pulverized, forming 

 an impalpable dust in dry weather and a miry day 



