It has been found by experience that the laying of this concrete should not be commenced before May, and that it should not be continued beyond the end of September (or middle of October, if the weather is very fine). Frost is fatal to it before it has become hard, and continuous cold wet weather retards considerably the hardening.

There can be no doubt that a pavement of this description for traffic that is not too heavy answers every requirement; for streets of greater traffic, genuine mastic asphalte should be used.

Before closing my remarks on artificial asphalte pavements, the following description of an American method may be interesting:

On a dry foundation is placed a coat of rough clinkers from anthracite coal or iron clinkers from a foundry, mixed with sand and tar in the proportions of 15 cubic feet of fine sifted ashes, 14¹⁄₂ cubic feet of pit sand, and 1¹⁄₂ cubic feet or 9 gallons of tar. This is laid about 3 to 4 inches thick and well rolled. Over this is placed a coating from 1 inch to 1¹⁄₂ inch thick, composed of 15 cubic feet of coarse sifted ashes, 15 cubic feet of clinkers, and 1¹⁄₄ cubic feet or 8 gallons of tar. It must be then well rolled and sanded, care having been taken that the materials are thoroughly mixed.

Gravel Footpaths.

—For the suburbs of a town and in the country, nothing looks so pretty as a gravel footpath.

The same rules that apply to a macadamised roadway apply to a gravel footpath. They must be well “bottomed,” and well drained and well rolled. Limestone or other stone chippings may with advantage be used with a pit gravel for constructing paths of this description, and a barrelled surface looks better and is more enduring than a hanging path. The following cross sections of footpaths will explain themselves better than any long description:

[Large illustration] (163 kB)

Gravel footpaths are sometimes tarred over when thoroughly consolidated. This must be done only when the weather is quite settled and fine: the least rain will spoil the whole operation; it consists in simply tarring over the surface of the footpath in the same manner that a gate or wall or any other substance would be tarred. The surface of the path must previously have been swept perfectly clean, and immediately as the tarring is completed, fine stone dust must be sprinkled on its surface; the traffic should be diverted from it for a few hours, and it is then ready.