332 



WALKS. 



smother should be so arrarigeu as to 

 carry off the surface-water from 

 rain or melting snows along the 

 edges of the walks, and the under- 

 ground water by drains beneath the 

 surface. On even surfaces even 

 though not level, this is attended 

 ■with little difficulty ; and one drain 

 under the centre of the walk, or on 

 one side of it will suffice for a 

 considerable length, -without any 

 branch drains to carry off the w^ater 

 which accumulates ; but where the 

 surface rises and falls alternately 

 it is not only necessary to have a 

 drain under the walk throughout 

 its whole length, but a branch drain 

 to some natural outlet is essential 

 at every change of surface. These 

 drains are not only intended to 

 carry off the underground water, 

 but also that which collects on the 

 surface, and iinds its way to the 

 sides ; and for this purpose there 

 are small cross di-ains formed at 

 certain distances, which communi- 

 cate from the sides to the centre, 

 and these side drains communicate 

 with the surface by a small up- 

 right tube or well, covered by an 

 iron grating or by a flagstone 

 pierced Avith hole?, to admit tlie 

 water. Sometimes the main drain, 

 instead of being formed under the 

 centre of the walk, is made at one 

 side, and sometimes in the case of 

 walks through a lawn, the drain is 

 made under the turf ; but in this 

 case, as in the other, the small cross- 

 drains communicate with it, and are 

 furnished with gratings on a level 

 with the surface of the sides of the 

 walk. In general these gratings 

 are placed close to the edge of 

 the walk, more especially when it 

 passes through dug ground edged 

 with box, or where there is little 

 ground to spare ; but when it 

 passes through a lawn, the gratings 

 are best jjlaced in small recesses in 



the turf at the sides. In the case 

 of dry soils with a porous subsoil of 

 gravel, sand, or rock, drains may 

 be dispensed with altogether ; and 

 in those parts of the country where 

 the kind of gravel used does not 

 bind so as to form a sufficiently 

 smooth and compact sm-face to 

 prevent the water from sinking 

 into it, the side gratings may be 

 dispensed with. In walks on very 

 uneven surfaces, such as where they 

 are conducted up and down de- 

 clivities, considerable care in the 

 construction is required, in order 

 to prevent the gravel from being 

 washed away during heavy rains or 

 the thawing of snow. Two thing.s 

 are requisite fur this purpose ; very 

 complete drainage, with gratings on 

 both sides, not more than two or 

 three yards apart ; and having the 

 surface of the walk raised much 

 higher in the middle than usual, so 

 as to throw the water immediately 

 to the sides, and never to admit of 

 a current in the direction of the 

 walk. The next requisite is a much 

 coarser gravel than usual, in con- 

 sequence of which the water of rain 

 or snow cannot wash aw^ay the 

 sandy particles. The most effective 

 mode, however, is to wash the 

 gravel quite clean, so as to leave no 

 pai-ticle smaller than a large goose- 

 berry, or larger than a small apple, 

 and to mix the whole with Roman 

 cement. Were it not for the dis- 

 : agreeable dark colour of asphalte, 

 i walks on steep declivities laid with 

 I this material would be preferable to 

 any others, as being by fiir the 

 1 most durable. 



In the operation of forming walks, 

 the first step, after the line has 

 been marked out, is to take the 

 levels of the surface, so as to deter- 

 mine the degree of inclination neces- 

 sary for carrying off the water, and 

 also what quantity of soil will have 



