204 THE BOOK OF THE LANDED ESTATE. 



small gravel into the pipes, and thus choking them. The lime above 

 the stones will assist in the prevention of weeds. 



The cost of such a walk depends so much upon the convenience of 

 materials, and the cost of labour in different districts, that I refrain from 

 giving any statement of cost. Good walks are sometimes made by dig- 

 ging out the soil to a depth of eighteen inches ; a line of drain-pipes is 

 then laid along each side of the excavation, having downfall-pipes at 

 every forty or fifty yards, and nearer than this where it may be neces- 

 sary. These downfall-pipes have small gratings at the top, placed a little 

 below the level of the walk, to carry off the surface-water. These drains, 

 and also that first described, should be connected with other drains in 

 the grounds. The bottom of the excavation is then filled with broken 

 bricks, rough gravel, or stones to within two or three inches of the grass, 

 box, or other edging, as the case may be ; the walk is then finished by 

 laying on gravel two inches thick. Roads and walks formed of asphalt 

 have of late years been extensively made. They are very firm and dur- 

 able when well made. When roads or walks of this description are 

 made, a foundation of stones is laid in the bottom, a few inches thick ; a 

 layer of concrete is then laid on about three inches thick, upon which 

 the asphalt is laid in a hot state. There are several tradesmen through- 

 out the country who do this by contract. The cost depends upon the 

 situation. 



Excellent walks are also made by pouring boiling gas-tar on a walk 

 after it has been finished in the ordinary way described; and a 'sprink- 

 ling of fine gravel is then put over the tar, smoothed over, and allowed 

 to cool, when it will be in a fit state to walk upon. 



SECTION 5. Bridges. 



I now come to make some remarks in reference to small bridges, 

 which are sometimes required on estates in the formation of roads. 

 Where bridges have to be made on a large scale, the aid of an experienced 

 engineer should of course be called in ; but for the erection of small 

 bridges under ordinaiy circumstances on an estate, this need not be 

 necessary. 



Bridges are made of stone, iron, and wood. In the construction of 

 either, the first and most important consideration is to secure an 

 unyielding foundation for the abutments, and also for the piers, if 

 there should be any, and no work of the kind need be attempted until 

 this is done. 



In the formation of a new farm-road on this estate some time ago, I 



