62 CONSTRUCTION AND MANAGEMENT OF SMALL GASWORKS. 



fully occupied on each side, a main on each side of the 

 street may be provided, but in the country, one line of 

 main has to serve both sides of the road. A very usual 

 plan is to lay it on the most populous side. Where there 

 are likely to be connections on both sides, it should be 

 well out towards the middle, and not hugging the gutter or 

 in the footwalk. Very often it happens that the business is 

 confined to one side of the road, as, for instance, a 

 thoroughfare skirting a private estate, or a public recrea- 

 tion ground. Under these circumstances, of course, there 

 is no advantage in keeping out towards the centre of the 

 road. Probably, the district surveyor may have something 

 to say on the point. If there is a long stretch of main to 

 be laid along a road having a border of grass on one or 

 both sides, as frequently happens in the South of England, 

 it may be desirable to lay the main under the turf, and 

 not in the road. There is a considerable saving in cost of 

 excavation, and the pipe is not exposed to the vibration of 

 passing traffic. 



The pipe must be laid deep enough not only to ensure 

 protection from frost and vibration, but to give the service 

 pipes a smart fall towards the main. In my experience, 

 1 8 inches depth is not sufficient for modern require- 

 ments. It does not afford sufficient protection from vibra- 

 tion, and the service pipes must be laid nearly level, or else 

 almost out of the ground at the gutter. Yet I have seen pipes 

 laid in the footwalk, on one side of a 36 feet wide road, and 

 only 1 8 inches deep ; with the result that services carried 

 over to the far side had to be laid with a fall away from 

 the main, and a bottle syphon fixed at the lowest part. A 

 depth of 24 inches clear is far preferable. It adds to the 

 cost of excavation, but the advantages secured are well 

 worth the extra outlay. 



