CONSTRUCTING ROADS AND WALKS. 



65 



broken up coarsely, may bo used, on this placing 2 inches of finer hard material, 

 making all as solid as possible with rammers. There should be no high centres to 

 either drives or walks, but only just enough curve allowed (see Figs. 32 and 33) 

 to throw off the water to the sides. The centre of a drive or walk 8 feet to 12 feet 

 in width may be from 1 inch to 1| inches above the edge level, adding ~ inch for 

 every additional 2 feet in width. The exact height is easily regulated by the use 

 of a central line of pegs levelled as advised in the case of edge formation, and these 

 pegs should not be drawn out till the time has arrived for surfacing over with binding 

 gravel. Two inches or rather more of this is needed, and it requires to be levelled very 

 carefully with the back of a rake, then closely trodden, again made even, and rolled 

 till it is firm and smooth. Newly-made drives and walks should be frequently rolled, 

 doing this at a time when the gravel will not be drawn up in the process. 



Drains are necessary not merely for the purpose of keeping water from collecting on 



Fig. 32. Section of Eoad, 



1, Drainage pipes ; 

 stones ; 3, smaller do, 

 facing gravel. 



coarse 

 4, svir- 



Fig-. 33. Section op Walk. 



1, Gully ; 2 drain pipe, 

 stones and gravel as shown. 



Fig. 34. Longitudinal Section of Walk. 



1, Catcli-pit ; 2, drainage pipes 

 leading into and out of gully. 



the bottoms of walks and drives, but also serve to carry away the top-water when 

 provision is made for collecting and transmitting the same to the drains underneath. 

 The slight curve given to the centre will throw the water to the sides, and this ought 

 further to be intercepted by gullies surmounted by iron gratings at intervals of from 

 20 feet to 40 feet apart, according to circumstances. In the case of somewhat steep 

 ascents these gullies or small catch-pits have to be the most frequent, as otherwise great 

 accumulations of water will quickly carry the gravel from the higher parts of the walks 

 or drives to the lower ground. Sometimes grips or bars have to be formed obliquely 

 across walks opposite to the gullies, these intercepting and preventing heavy rushes 

 of water. They may be formed with a paved front of flat bricks with other bricks on 

 edge to form a slightly higher back, or strong oak quartering may be substituted, the 

 latter proving the more durable where there is heavy traffic. The gully-holes should 

 be from 9 inches to 1 foot deeper than the drain pipes, the latter passing through the 

 centre as shown in Fig. 34, the extra depth allowing space for mud to collect without 



VOL. T. K 



