The Construction and Maintenance of Roads. 555 



or whiustones are preferable to limestones, as neither the latter nor 

 the various kinds of sandstone are snfllciently strong. Flint, gravel, 

 and pebbles will not alone form a solid bottom, though they may be 

 used in conjunction with other stone. Upon the surface, both gravel 

 and flint wears down rapidly. A mixture of flint stone and the best 

 kinds of Kentish rag makes a good and durable road ; and if a pro- 

 portion of fine or broken shingle be added, its wearing powers are 

 much increased. 



All the materials for repairing roads should be deposited at their 

 sides during the summer months, and broken and put on before the 

 beginning of winter, as they seldom settle well after frosts set in. 

 Where the materials available for coating a road are not of a nature 

 to bind well together, a more compact surface may be obtained by 

 floating it with thick lime-water into which has been stirred a small 

 quantity of iron rust, or some of the flakes which fall from the red- 

 hot iron under the blows of the smith's hammer. The iron produces 

 an oxidation which causes the whole mass to adhere firmly. Some 

 kinds of limestone also, when broken down finely, and laid on to a 

 considerable thickness, will partially unite and form a road sufficient 

 to carry a fair load over any ground upon which a man could pre- 

 viously walk with safety. 



The subject of laying out and constructing wood-rides, with some 

 general remarks on the theory of road-making, must be reserved for a 

 future paper. 



{To de continuedi) 



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