The second is sewerage.
I shall first deal with the sewerage of the metropolis.
Of the Quantity of Metropolitan Sewage.
Having estimated the gross quantity of wet house-refuse produced throughout London in the course of the year, and explained the two modes of removing it from the immediate vicinity of the house, I will now proceed to set forth the quantity of wet house-refuse matter which it has been ascertained is removed with the contents of London sewers.
An experiment was made on the average discharge of sewage from the outlets of Church-lane and Smith-street, Chelsea, Ranelagh, King’s Scholar’s-pond, Grosvenor-wharf, Horseferry-road, Wood-street, King-street, Northumberland-street, Durham-yard, Norfolk-street, and Essex-street (the four last-mentioned places running from the Strand). The experiments were made “under ordinary and extraordinary circumstances,” in the months of May, June, and July, 1844, but the system is still the same, so that the result in the investigation as to the sewage of the year 1844 may be taken as a near criterion of the present, as regards the localities specified and the general quantity.
The surface drained into the outlets before enumerated covers, in its total area, about 7000 acres, of which nearly 3500 may be classed as urban. The observations, moreover, were made generally during fine weather.
I cannot do better by way of showing the reader the minuteness with which these observations were made, than by quoting the two following results, being those of the fullest and smallest discharges of twelve issues into the river. I must premise that these experiments were made on seven occasions, from May 4 to July 12 inclusive, and made at different times, but generally about eight hours after high water. In the Northumberland-street sewer, from which was the largest issue, the width of the sewer at the outlet was five feet. In the King-street sewer (the smallest discharge, as given in the second table) the width of the sewer was four feet. The width, however, does not affect the question, as there was a greater issue from the Norfolk-street sewer of two feet, than from the King-street sewer of four feet in width.
| Northumberland Street. | ||
| Date. | Velocity per second. | Quantity discharged per second. |
|---|---|---|
| Feet. | Cubic Feet. | |
| May 4 | 4·600 | 10·511000 |
| „ 9 | 4·000 | 6·800000 |
| June 5 | 4·000 | 6·800000 |
| „ 10 | 4·600 | 10·350000 |
| „ 11 | 4·920 | 12·300000 |
| „ 16 | 3·600 | 5·940000 |
| July 12 | 2·760 | 3·394800 |
| 56·095800 | ||
| Being Mean Discharge per second | 8·013685 | |
| Ditto per 24 hours | 692382· | |
| King Street. | ||
| May 4 | ·147 | ·021756 |
| „ 9 | ·333 | ·079920 |
| June 5 | ·170 | ·020400 |
| „ 10 | ·311 | ·064688 |
| „ 11 | ·300 | ·048000 |
| „ 16 | ·101 | ·004040 |
| July 12 | ·103 | ·008240 |
| ·247044 | ||
| Mean Discharge per second | ·035292 | |
| Ditto per 24 hours | 3049· | |
Here we find that the mean discharge per second was, from the Northumberland-street sewer, 692,382· cubic feet per 24 hours, and from the King-street sewer, 3049 cubic feet per 24 hours.
The discharge from the principal outlets in the Westminster district “being the mean of seven observations taken during the summer,” was 1,798,094 cubic feet in 24 hours; the number of acres drained was 7006. The mean discharge per acre, in the course of 24 hours, was found to be about 256 cubic feet, comprising the urban and suburban parts.