But there are still the street or gully-drains for the surface-water to be estimated. In the Holborn and Finsbury division alone, the length of the “main covered sewers” is said to be 83 miles; the length of “smaller sewers” to carry off the surface-water from the streets 16 miles; the length of drains leading from houses to the main sewers, 264.
Now, if there be 16 miles of gully-drains to 83 miles of main covered sewers, and the same proportion hold good throughout the 58 square miles over which the sewers extend, it follows that there would be about 200 miles of gully-drains to the gross 1100 miles of sewers.
But this is only an approximate result. The length and character of the gully-drains I find to vary very considerably. If the streets where the gully-grates are found have no sewer in a line with the thoroughfare, still the water must be drained off and conveyed to the nearest sewer, of any class, large or small, and consequently at much greater length than if there were a sewer running down the street. Neither is the number of the gully-holes any sure criterion of the measurement of the gully-drains, for where the intersections are, and consequently the gully-holes frequent, a number, sometimes amounting to ten, are made to empty their contents into the same gully-drain. Neither do the returns of yearly expenditure, presented to Parliament by the Metropolitan Court of Sewers, supply information. But even if the exact length, and the exact price paid for the formation of that length, were given, it would supply but the year’s outlay as regards the additions or repairs that had been made to the gully-drains, and certainly not furnish us with the original cost of the whole.
One experienced informant told me—but let me premise that I heard from all the gentlemen whom I consulted, a statement that they could only compute by analogy with other facts bearing upon the subject—was confident, that taking only 1200 miles of public way as gully-drained, that extent might be considered as the length of the gully-drains themselves. Even calculating such drains to run from each side of the public way, which is generally the case, I am told that, considering the economy of underground space which is now necessary, the length of 1200 miles is as fair an estimate for gully-drainage (apart from other drainage) as for the length of the streets so gullied.
Hence we have, for the gross extent of the whole sewers and drains of the metropolis, the following result,—
| Miles. | |
| Main covered sewers | 1100 |
| House-drains | 2840 |
| Gully-drains for surface-water of streets | 1200 |
| Total length of the sewers and drains of the metropolis | 5140 |
The island of Great Britain, I may observe, is, at its extreme points, 550 miles from north to south, and 290 from east to west. It would, therefore, appear that the main sewers of the capital are just double the length of the whole island, from the English Channel to John-o’-Groats, and nearly three times longer than the greatest width of the country. But this is the extent of the sewerage alone. The drainage of London is about equal in length to the diameter of the earth itself!
Of the Cost of Constructing the Sewers and Drains of the Metropolis.
The money actually expended in constructing the 1100 miles of sewers and 4000 miles of drains, even if we were only to date from Jan. 1, 1800, is not and never can be known. They have been built at intervals, as the metropolis, so to speak, grew. They were built also in many sizes and forms, and at many variations of price, according to the depth from the surface, the good or bad management, or the greater or lesser extent of jobbery or “patronage” in the several independent commissions. Accounts were either not presented in “the good old times,” or not preserved.
Had the 1100 miles of sewers to be constructed anew, they would be, according to the present prices paid by the Commissioners—not including digging or such extraneous labour, but the cost of the sewer only—as follows:—