The effective watering of streets and roads in any town during the summer months is an important matter, not only on sanitary grounds, but also from the fact that considerable damage may be caused in the neighbouring shops, warehouses, and dwellings, if something is not done to prevent the clouds of detritus and decaying refuse, of which the dust is composed, from being blown about. In the metropolis of London alone, the watering of the streets and roads employs, in addition to a staff of surveyors, inspectors, and foremen, about 1,500 men, and an equal number of horses and carts; and in order to lay the dust effectually, about 30,000 tons of water must be spread upon the streets every dry day, the cost of this gigantic work being nearly ￡200,000 per annum upon an average of 120 days, when watering becomes necessary.
The most commonly known method in this country for watering the streets and roads of our towns is that of carrying the water in wheeled barrels, carts,[74] or vans, and distributing it therefrom through a perforated pipe upon the surface of the road as the vehicle is drawn along by a horse attached to the shafts.
The points of importance to be considered under this system are as follows:—
(1.) The number and position of the stand posts or hydrants, from which the water carts are to be filled, and whether they shall be "swan neck" stand posts or "valve" hydrants.
(2.) The size and form of the body of the water carts, as regards its cubical capacity, its weight, strength, lightness of draught, durability, width of spread, and shape of jet, so as to ensure evenness of supply without leaving pools of water or dry patches after it has passed, or causing that unpleasant cloud of dust which so often follows the cart.
A wonderful improvement in all these respects has been lately effected by the introduction of Mr. E. H. Bayley's Patent Hydrostatic Van, of which I shall speak more in detail hereafter.
(3.) Another point of some importance is the material of which the hose shall be constructed, if valve hydrants and not swan necks are existing. My opinion is that it should be of leather, as being roughly handled and little cared for; canvass hose, although[75] the cheapest, is not sufficiently durable, and is consequently the dearest in the end; and (4), lastly, the driver and horse should both be of some intelligence. A check should also, if possible, be kept upon the former to see that he performs his allotted task, and does his proper number of rounds. Mr. Bayley has also introduced for this purpose a "Tell Tale Indicator," which records automatically the quantity of water used; it cannot be tampered with, and registers on a dial outside the van each load of water delivered, so that the surveyor or other officer can see at a glance whether the driver is attending to his work, or whether the hot weather has made him find his throat drier than the roads, and he has been spending some of his time in moistening it. In the year 1856, Mr. Scott, C.E., the chief surveyor of the parish of St. Pancras, kept an account of the daily round of an ordinary water cart, when he found that through an average working day of 10? hours, exclusive of the breakfast and dinner hours, the cart took one hour and twenty minutes filling, fifty minutes only in distributing the water on the roads, and eight hours and seven minutes in travelling to spread the water and back to the stand posts. It was obvious that these were placed too far apart, and by the subsequent introduction of additional standposts Mr.[76] Scott found, in the year 1867, that the filling occupied two hours, the distribution one hour and thirty minutes, and the travelling to and fro six hours and thirty minutes, so that it may be assumed, with an ordinary two-wheeled water cart, that two-thirds of the day is spent in travelling, one-fifth in filling, and about one-seventh in the actual spreading.
To many of my readers Bayley's Van is probably as familiar as it is to me, but it may notwithstanding be well to describe it. It is a handsome vehicle in appearance, the body being made of wrought iron plates, and measures 8 ft. in length by 4 ft. 8 in. in breadth, and 2 ft. in depth, holding 450 gallons. It is mounted on springs upon four wheels hung upon Bayley's patent axles, and has a pair of light shafts; it can easily be fitted with a break for hilly roads, and there being no weight at any time upon the horse's back, he is relieved from any severe strains.
By means of an adjustable valve the flow of water can be regulated according to the state of the roads, and, if necessary, a double valve can be inserted, so that either side of the distributor can be at work when only half the width is required, or when passing a carriage or narrow spaces.
The branch pipe is of uniform size, except close to the spreader, where it enlarges in order to avoid[77] friction, and this is assisted by the branch pipe being shaped into a cycloidal curve on each side.
In order to obtain as great a pressure as possible upon the jets of the distributing pipe, and thus to give the side jets a greater trajectory than they otherwise would have, the tank is elevated as high as is consistent with the conditions of draught. At the same time, the distributing pipes are placed as near to the ground as convenient, so that the maximum extent of distribution is obtained, and that with less dust and splashing than in the ordinary system. The holes in the distributing pipe instead of being drilled in straight lines, are on a curved line, which rises along the length of the pipe from the centre towards the ends. This has been found necessary, in order that the distributing pipe may be placed low, and at the same time advantage be taken of the width of the trajectory of the jets.
Comparing the work of one of these vans with that reported upon by Mr. Scott, it is found that the van occupies nine minutes in filling, six minutes in spreading the water, and only three hours and fifteen minutes in travelling to and fro, so that in seven hours it accomplishes as much work as the ordinary water cart effects in ten hours.
In Edinburgh, where a trial of one of these vans[78] took place against one of the old carts, it was found that the van spread the water a width of 20 feet, while the old cart only covered 14 feet; the van conveyed the water 1,731 feet, and the cart only 951 feet. The superficial area watered by one load of the van was 34,620 feet, and by the old system only 13,314 feet. When we consider the time that is lost in travelling to and from the stand pipe, what a large saving this represents in the cost of this work.
Mr. Tomkins, C.E., the surveyor of the important Metropolitan parish of St. George, Hanover Square, has made the following comparative experiments with one of Bayley's vans as against an ordinary cart:—
Contents in Gallons. No. of Loads to cover beat. Total quantity of Water. Time. Difference. Gain per Cent.
Hrs. Mnts. Hrs. Mnts.
Van 450 5? 2475 1 23 — —
No. 4 Cart 225 11 2475 1 50 0 27 24?
Van 450 5? 2475 1 38 — —
No. 9 Cart 237 11 2607 2 10 0 32 25
Van 450 6 2700 1 45 — —
No. 15 Cart 290 11 3190 2 10 0 25 19?
Van 450 8 3600 2 15 — —
No. 19 Cart 260 17 4420 3 30 1 15 36
This shows a mean gain of 26 per cent. in favour of the van, and the following tables made by an[79] inspector in 1873, showing the actual occupation of the ordinary carts and Bayley's vans during a day's work, are extremely interesting, as showing that while the van is engaged in spreading the water the time of the cart is wasted in travelling to and from the stand posts, and when it is borne in mind also that the van spreads water more widely than the cart, there can be no doubt that a saving of at least 30 per cent. can be effected by the substitution of these vans for the old-fashioned cart.
CARTS.
Filling. Travelling
Full. Travelling
Empty. Waiting, &c. Spreading.
&n............