[20] Vide ‘Minutes of Proceedings of the Institution of Civil Engineers,’ vol. lx.
[21] Vide ‘Annales industrielles de Paris,’ Oct. 21st and Nov. 4th, 1877.
[22] Vide ‘Annales industrielles de Paris.’
[23] A report of the Paddington Vestry on “wood and other pavements,” (1878) states macadam as a mud producing material is twelve times worse than wood, and six times worse than granite cubes.
[24] This is also sometimes called “stocking” or “chequering,” and consists of making furrows across a roadway with a sharp pickaxe, about a couple of inches in depth, thus removing any irregularities, and also allowing the new metal to bed properly.
[25] In Birmingham, good cleansing is said to have reduced the amount of metal necessary for the maintenance of the roadways from 20,000 tons per annum to 13,000 tons.
CHAPTER VI.
ROAD METAL AND BREAKING.
The only true test of the fitness of any stone for use as a road metal is by an experimental trial upon a certain length of roadway; but in making the first selection for such trials it is well to make the following investigations:—
(1.) Ascertain from local persons, such as masons, quarrymen, and others, their opinion of the qualities of the stones in the neighbourhood.