By the application of capital and machinery, the cost of conveyance of substances in suspension in a fluid, even at the water companies’ prices, may be rendered thirty and even more than forty times as cheap as collection by hand labour and removal by cartage. In the metropolis, where the persons who water the roads may obtain water gratuitously from pumps, the water supplied by stand-pipes by some of the water companies at 1l. per 100 tons, is found to be twice as cheap as the mere labour of pumping the water into the cart. By proper hydraulic arrangements heavy solid substances may be swept away through the iron pipes.
These means which science gives of cheapening the cost of the conveyance of refuse from houses, will be available also in extending and completing the cleansing of the towns, of removing the filth which oppresses the poorer districts, and rendering the whole of it available, in the best form, for future use as manure.
The expense of cleansing the streets of the township of Manchester is 5,000l. per annum. For this sum the first class of streets, namely, the most opulent and the large thoroughfares, are cleansed once a-week, the second class once a-fortnight, and the third class once a-month. But this provision leaves untouched, or leaves in the condition described in Dr. Baron Howard’s report, the courts, alleys, and places where the poorest classes live, and where the cleansing should be daily. There are abundance of recommendations to the effect, “Let it be ordered that the streets be properly cleansed;” but in this instance the cost of cleansing the whole of what is properly the same town, Salford, and the out-townships, would be 8,000l. or 10,000l. per annum; and such a recommendation, under the existing modes of management, is equivalent to saying, let 20,000l. or 30,000l. of additional rates be expended, and 40,000 or 60,000 additional loads of refuse be removed. In other large towns, the service and the expense is on a similar scale. At the rate of expense of one large parish, the present cost of cleansing in the metropolis may be estimated at about 40,000l. per annum. This expense, however, is generally repaid by the sale of the coal-ashes, which are used in the manufacture of bricks.
Though the refuse of the poorer districts is often taken and sold, the immediate objection to the extension of the services of the scavenger to them is the increase of the immediate expense, which it is practically necessary to consider in detail, although if there were no compensation by the sale of any coal-ashes or house refuse, and if the occupants were required to pay for the cleansing at the rate of one of the opulent parishes in the metropolis, that is at the rate of 4s. per house per annum, which would be less than a penny per tenement for the weekly street cleansing; or in the poorer districts, where there are mostly two families to a tenement, a charge of less than one halfpenny per week for cleansing, would be found to be good economy, as one means of diminishing the existing heavy charge of sickness, not to speak of the wear and tear of clothes.
Two-thirds of the usual expense of street cleansing is the expense of cartage, which, with a proper adaptation of the sewers, is wholly unnecessary. The exclusive use of hand-labour in street-sweeping is pronounced by competent judges to be a mere barbarism, and several machines have been invented which demonstrate that by mechanical power, moved by horses, the cleansing may be effected in a far shorter time. Some of these scrape the mud in ridges to the sides, where it remains until it can be lifted and carted away. But this is objected to as inconvenient by the shopkeepers, and the scavengers object that it is no convenience to them, inasmuch as raking it in heaps prevents the evaporation of the liquid, and increases the cartage; and, moreover, that the process of sweeping by hand is as quick as the carts can return for its removal. A machine has been used at Manchester which rapidly and cleanly sweeps the level surfaces of the streets into a cart; but there is still the encumberance of the labour, and cost and delay of carting the refuse to a place of deposit, which may be several miles distant, and returning to reload. The value of a process of street-cleansing is proportioned to the rapidity with which it is performed, but at present it is usually delayed until the sun or the air has done a large portion of the work by the evaporation of the moisture, commonly however to the deterioration of the air of the town and the health, and also to the deterioration of the value of the refuse.
On examining these obstructions to the cleanliness and salubrity of our towns, it became apparent that the expensive and slow process of the removal of the surface refuse of the streets by cartage might be dispensed with, and the whole at once carried away by the mode which is proved, in the case of the refuse of houses, to be the most rapid, cheap, and convenient, namely, by sweeping it at once into the sewers, and discharging it by water.
The sewerage of the metropolis, though it is a frequent subject of boast to those who have not examined its operations or effects, will be found to be a vast monument of defective administration, of lavish expenditure, and extremely defective execution. The general defect of these works is, that they are so constructed as to accumulate deposits within them; that the accumulations remain for years, and are at last only removed at a great expense, and in an offensive manner, by hand-labour and cartage. The effect is to generate and retain in large quantities before the houses the gases which it is the object of cleansing to remove. In the course of the present inquiry instances have been frequently presented of fevers and deaths occasioned by the escapes of gas from the sewers into the streets and houses. In the evidence given before the Committee of the House of Commons, which received evidence on the subject in 1834, one medical witness stated, that of all cases of severe typhus that he had seen, eight-tenths were either in houses of which the drains from the sewers were untrapped, or which, being trapped, were situated opposite gully-holes; and he mentioned instances where servants sleeping in the lower rooms of houses were invariably attacked with fever. It was proposed as a remedy to prevent the escape of the noxious effluvia by trapping them, but this was refused on the ground of the danger to the men, who must enter the sewers to clean them, from the confined gas. In one of the circulars the reason assigned for allowing the escape of the gas into the streets is that if it were confined in the sewers it might impede the flow of the water. It was then proposed to allow the escape of the noxious gases through chimneys constructed at certain distances. But this was decided to be an experiment, and the Committee did not feel themselves authorized to make experiments. Instances were adduced where it had been found necessary either to trap or to remove gully-holes in the vicinity of butchers’ shops, to avoid the injurious effects of the effluvium upon the meat. Similarly mischievous effects of the defective construction and management of the sewers are commonly displayed in the medical reports from the provincial towns, and they have been incidentally noticed in the passages already cited.
It may be mentioned as another instance of the absence of appropriate knowledge that has governed these structural arrangements, that a large proportion of the most expensive sewers are constructed with flat bottoms. In proportion as the water is spread the flow is impeded, and the deposit of matter it may hold in suspension increased. Mr. Roe, a civil engineer, who, much to the honour of the Holborn and Finsbury district of sewers, has been appointed to the care of their sewers, and is perhaps the only officer having the experience and qualifications of a civil engineer, states, that as compared with sewers or drains with bottoms of a semicircular form, those with flat bottoms invariably occasion a larger amount of deposit; and with the same flow of water, the difference of construction occasions a difference of more than one-half in the deposit which is left. By the common and most expensive form, the drains are apt to be choked up with noxious accumulations; by being built with flat sides (instead of with curved sides, which give the strength of an arch) they are apt in clayey and slippery ground to be forced in. The expense of the improved form is nearly one-fourth less than those in general use. Mr. Roe, whose evidence, which is corroborated by the evidence of other engineers, is given in the Appendix, was asked,—
In respect to the levels, how have you found the sewers?—They appear to have been entirely constructed with reference to the locality, to drain to the nearest outlet, and not on an extended view for the whole district, or with any view to sewerage on a large scale. In the Holborn and Finsbury divisions the Commissioners now adopt a series of levels suited from the lowest outlets to the surrounding districts.
Have you heard of any alterations made in the surrounding districts on the same principle?—I have heard of none as adopted generally. The City have lowered several of their outlets; and the chairman of the Westminster Commission has had the subject under consideration for some time.