THERE is no official account precisely defining the length of the London sewerage; but the information acquired on the subject leaves no doubt as to the accuracy of the following facts.

About miles of sewers of the metropolis may be said to have been surveyed; and it is known that from to miles more constitute a portion of the metropolitan sewerage; this, too, independently of that of the City, which is miles. Altogether I am assured that the sewers of the urban part of London, included within the square miles before mentioned, measure miles.

The classes of sewers comprised in this long extent are pretty equally apportioned, each a , or miles, of the , , and classes respectively. Of this extent about miles are still, in the year , sewers!—to say nothing of the great open sewer, the Thames. The open sewers are found principally in the Surrey districts, in Brixton, Lewisham, Tooting, and places at the like distance from the more central parts of the Commissioners' jurisdiction. These open sewers, however, are disappearing, and it is intended that in time no such places shall exist; as it is, some miles of them are inclosed yearly. The open sewers in what may be considered more of the heart of the metropolis are a portion of the Fleet-ditch in Clerkenwell, and places in and , or about miles in the interior to miles in the exterior portion of the capital. These are national disgraces.

The miles above-mentioned, however, include only the sewers, comprising neither the house nor gully-drains. According to the present laws, all newly-built houses must be drained into the sewers; and in there were applications from the western districts alone to the Commissioners, for the promotion of the drainage of that number of old and new houses into the sewers, the old houses having been previously drained into cesspools.

I am assured, on good authority, that fully onehalf of the houses in the metropolis are at the present time drained into the sewers. In street, about a century old, containing in the portion surveyed for an official purpose, on the sides of the way, houses, the number was found to be equally divided—half the drainage being into sewers and half into cesspools. The number of houses in the metropolis proper, of square miles area, is . The majority, as far as is officially known, are now drained into the public sewers, or into private or branch sewers communicating with the larger public receptacles, so that—allowing houses to be included in the square miles of the urban sewerage, and admitting that some wretched dwelling-places are not drained at all—it is reasonable to assume that at least houses within this area are drained into the sewers.

The average length of the house-drains is, I learn from the best sources, feet per house. The builder of a new house is now required by law to drain it, at the proprietor's cost, feet, if necessary, to a sewer. In some instances, in detached houses, where the owners object to the cesspool system, a house drain has been carried feet to a sewer, and sometimes even farther; but in narrow or moderately wide streets, from to feet across, and in alleys and narrow places (in case there is sewerage) the house drains may be but from to feet. Both these

The length of the house-drainage of the more central part of London, assuming houses to be drained into the sewers, and each of such drains to be on the average feet long, is, then, feet, or about miles.

But there are still the street or gully-drains for the surface-water to be estimated. In the and Finsbury division alone, the length of the "main covered sewers" is said to be miles; the length of "smaller sewers" to carry off the surface-water from the streets miles; the length of drains leading from houses to the main sewers, .

Now, if there be miles of gully-drains to miles of main covered sewers, and the same proportion hold good throughout the square miles over which the sewers extend, it follows that there would be about miles of gullydrains to the gross 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 , 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 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.

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 miles of public way as gully-drained, that extent might be considered as the length of the gullydrains 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 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,—

The island of Great , I may observe, is, at its extreme points, miles from north to south, and 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 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!