----------+-----------+----------+----------+--------- | | | | | | | | | | | | | | | | Total Des- |Maintenance|Scavenging|Gravelling| Annual cription |per Square |per Square|per Square|Cost per of | Yard per | Yard per | Yard per | Square Pavement.| Annum. | Annum. | Annum. | Yard. ----------+-----------+----------+----------+--------- | _s._ _d._ | _d._ | _d._ |_s._ _d._ No. 6. | | | | Bituminous| | | | Concrete | 0 9 | 2·4 | .. | 1 1·4 Pavement | | | | | | | | No. 7. | | | | Wood | 0 1·0 | 2·7 | 5·0 | 1 8·5 Pavement | | | | | | | | No. 8. | | | | Macadam | 1 0 | 8·0 | Nil | 1 11·4 Pavement | | | | ----------+-----------+----------+----------+--------- In concluding this chapter upon wood paving, I will give a specimen specification for work of this description. _Excavation._--Excavate the ground to a depth of -- inches below the level of the proposed finished surface of the roadway.[86] The formation surface thus excavated must be well watered and rolled or punned if found necessary, and any soft or made earth removed to such a depth as may be found to be sufficient.[87] _Foundation._--Upon the excavated formation surface a bed -- inches thick of concrete is to be laid, composed of one part of good approved Portland cement to two of fine, sharp river sand, and three of clean river ballast or broken stone. The concrete to be finished off with an even and smooth top surface conforming with the contour line of proposed finished roadway. _Wood Blocks._--Upon the concrete thus laid, and after it has sufficiently set, wood blocks are to be laid.[88] These blocks must be of the best description of Baltic red timber[89] (or such other timber as shall be specified), sound and thoroughly well seasoned, free from all sap, shakes, large and loose knots or other defects, and any that may be rejected by the surveyor as unfitted for the work shall be at once removed from the works or broken up. The blocks must not be less than 6 inches or more than 12 inches in length by 3 inches in width and 6 inches in depth, they are to be carefully laid with the fibre of the wood placed vertically, their ends must butt with close joints to each other, and each course must be kept ³⁄₈ of an inch apart by means of wooden laths, which are afterwards removed.