Hence, according to the above calculations, we have the following

_Gross Estimate of the Cost of the Sewers and Drains of the Metropolis._

£

1100 miles of main covered sewers 3,500,000

2840 miles of house-drains 3,000,000

1200 miles of gully or street drains 1,000,000

---- ---------

5140 miles of sewers and drainage = 7,500,000

London Labour and the London Poor, Vol. 2 · 第 307 / 558 题