Modern Gasworks Practice

256 MODERN GASWORKS PRACTICE ably curtailed. The latter result is said to be due to the floats retaining the gas in longer contact with the hot liquid in the hydraulic main than is the case in ordinary working. Fig. 169.—Hydraulic Main with Ascension and Dif Pipes, Clbaning Hole, and Common Gas and Tar Discharge. Droby System. H. E. Bloor and J. B. Fenwick have introduced a hydraulic main of a new type, the chief object of which is to avoid the necessity for tar mains, and to permit of the easy removal of deposits of thick tar. The main, is in one 'S E E E G cz Fig. 170.—Continuous Hydkaulic Main with End Gas and Liquor Take-off, showing Eitect ok Oscillation dv,: to Exhauster Pull. continuous length of 60 feet; and it slopes 2J-inches per setting to the tar tower. Division plates between each setting allow any setting or settings to be left-off; and tlie main can be carried over the end of the beuch