London Labour and the London Poor, Vol. 2

by Henry Mayhew

“We first used a machine,” says Mr. J. Lysander Hale, “in the form of a plough and harrow combined; a horse dragged it through the deposit in the sewer; one man attended the horse, and another guided the plough. The work done by this machine, in cutting a channel through the soil and causing the water to move through it quickly, was effectual to remove the deposit; but as the sewer is a tidal sewer, and its sole entrance for a horse being its outlet, the machine could only be used for a small part of any day. Sometimes with a strong breeze up the river, the tide would not recede sufficiently to permit the horse to get in at all (and it did not appear advisable to incur the expense of 50l. to build a sideway entrance for the animal), so that under these circumstances we were obliged to discontinue the use of the horse and plough; which, under other circumstances, would have been very effective.” From this time, I understand, the sewers of London have remained unploughed by means of horse labour.

But the plough was not altogether abandoned, and as horse-power was not found very easily applicable, water-power was resorted to. The plough and harrow were attached to a barge, which was introduced into the sewer. The sluice gates were kept shut until the ebb of the tide made the difference of level between the contents of the sewer and the surface of the Thames equal to some eight feet. “The gates were then suddenly opened, and the rapid and deep current of water following, was then sufficient to bring the barge and plough down the sewer with a force equal to five or six horse-power.”

This last-mentioned method was also soon abandoned. We now come to the more approved plan of “flushing.”

“The term ‘flushing sewers’ implies,” says Mr. Haywood, in his Report, “cleansing by the application of bodies of water in the sewers; this is periodically effected, varying in intervals according to the necessities of the sewerage or other circumstances.”

The flushing system has a two-fold object, viz., to remove old deposits and prevent the accumulation of new. When the deposit is not allowed to accumulate and harden, “flushing consists,” says Mr. Haywood, “simply in heading back and letting off flush at once” (hence the origin of the term) “that which has been delivered into the sewers in a certain number of hours by the various houses draining into them, diluted with large quantities of water specially employed for the purpose.”

Though the operation of “flushing” is one of modern introduction, as regards the metropolis—one, indeed, which may be said to have originated in the modern demand for improved sanitary regulations—it has been practised in some country parts since the days of Henry VIII.

Flushing was practised also by those able engineers, the ancient Romans. One of the grand architectural remains of that people, the best showing their system of flushing, is in the Amphitheatre at Nismes, in France. The site of the ruined amphitheatre presents a large elliptical area, 114,251 superficial feet comprising its extent. Around the arena ran a large sewer 3 feet 6 inches in width, and 4 feet 9 inches in height. With this sewer, elliptical in shape, 348 pipes communicated, carrying into it the rain-fall and the refuse caused by the resort of 23,000 persons, for the seats alone contained that number. “The system of flushing, practised here,” says Mr. Cresy, “with such advantage, deserves to be noticed, there being means of driving through this elliptical sewer a volume of water at pleasure, with such force that no solid matter could by any possibility remain within any of the drains or sewers. An aqueduct, 2 feet 8 inches in width, and 6 feet in height, brought this water from the reservoirs of Nismes, not only to fill but to purge the whole of these sewers; after traversing the arena, it deviated a little to the south-west, where it was carried out at the sixth arcade, east of the southern entrance. Man-holes and steps to descend into this capacious vaulted aqueduct were introduced in several places; and there can be no doubt that by directing for some hours such a stream of water through it, the greatest cleanliness was preserved throughout all the sewers of the building.”

The flushing of sewers appears to have been introduced into the metropolis by Mr. John Roe in the year 1847, but did not come into general use till some years later. There used to be a partial flushing of the London sewers twelve years ago. The mode of flushing as at present practised is as follows:—

In the first instance the inspector examines and reports the condition of the sewer, and receives and issues his orders accordingly. When the sewer is ordered to be flushed—and there is no periodical or regular observance of time in the operation—the men enter the sewers and rake up the deposit, loosening it everywhere, so as to render the whole easy to be swept along by the power of the volume of water. The sewers generally are, in their widest part, provided with grooves, or, as the men style them, “framings.” Into these framings are fitted, or permanently attached, what I heard described as “penstocks,” but which are spoken of in some of the reports as “traps,” “gates,” or “sluice gates.” They are made both of wood and iron. By a series of bolts and adjustments, the penstocks can be fixed ready for use when the tide is highest in the sewer, and the volume of water the greatest. They then, of course, are in the nature of dams, the water having accumulated in consequence of the stoppage. The deposit having been loosened, the bolts are withdrawn, when the gates suddenly fly back, and the accumulated water and stirred-up sewage sweeps along impetuously, while the men retreat into some side recesses adapted for the purpose. The same is done with each penstock until the matter is swept through the outlet. The men always follow the course of this sewage-current when the sewer is of sufficient capacity to enable them to do so, throwing or pushing forward any more solid matter with their shovels.

“To flush we generally go and draw a slide up and let a flush of water down,” said one man to me, “and then we have iron rakers to loosen the stuff. We have got another way that we do it as well; one man stands here, when the flush of water’s coming down, with a large board; then he lets the water rise to the top of this board, and then there’s two or three of us on ahead, with shovels, loosening the stuff—then he ups with this board and lets a good heavy flush of water come down. Precious hard work it is, I can assure you. I’ve had many a wet shirt. We stand up to our fork in the water, right to the top of our jack-boots, and sometimes over them.” “Ah, I should think you often get over the top of yours, for you come home with your stockings wet enough, goodness knows,” exclaimed his wife, who was present. “When there’s a good flush of water coming down,” he resumed, “we’re obligated to put our heads fast up against the crown of the sewer, and bear upon our shovels, so that we may not be carried away, and taken bang into the Thames. You see there’s nothing for us to lay hold on. Why, there was one chap went and lifted a slide right up, when he ought to have had it up only 9 or 10 inches at the furthest, and he nearly swamped three of us. If we should be taken off our legs there’s a heavy fall—about 3 feet—just before you comes to the mouth of the sewer, and if we was to get there, the water is so rapid nothing could save us. When we goes to work we nails our lanterns up to the crown of the sewer. When the slide is lifted up the rush is very great, and takes all before it. It roars away like a wild beast. We’re always obliged to work according to tide, both above and below ground. When we have got no water in the sewer we shovels the dirt up into a bank on both sides, so that when the flush of water comes down the loosened dirt is all carried away by it. After flushing, the bottom of the sewer is as clean as this floor, but in a couple of months the soil is a foot to 15 inches deep, and middling hard.”