The brushes of a machine last about 180 hours constant work, and then the old stocks can be easily refilled with bass at no great cost. The comparative work which can be done by a sweeping machine is about 11 to 1 of that effected by manual labour, so that the economy involved by the former method is evident.
The strength and durability of the brooms used for the work of sweeping the streets is of some importance, as affecting the ultimate cost of the work, and some care and skill is required in their selection. Bass brooms are better than birch brooms for this purpose, and the bass of which the brooms are made should be sufficiently stout and of regular thickness; it should be tough and elastic, not old, dry, and brittle, each knot should be of uniform size and be firmly set, and the number of knots in each broom head is also a matter of choice. A convenient and fair test of the soundness of a broom is to soak it for a few days in water before issuing it to the sweeper, and then note the time it will last. The handles of the brooms should be made of alder wood.
On the question of the extra work involved in street cleansing by its bad construction or by the materials of which it is constructed, climate must be considered, as well as the amount of traffic it has to bear, and also its gradient and the habits of the people residing in it.[166]
The Superintendent of the Scavenging Department at Liverpool has made some observations and obtained some valuable information on these points, which he has detailed in a report he presented to the Health Committee of that borough in the year 1877, an abstract of which is as follows:
Gross Cost for Each Time of Cleansing 10,000 Yards Superficial of
Different Descriptions of Roadway in the Borough of Liverpool.
| Street. | Description of Pavement. | When paved. | Condition of repair of Roadway. | Area of Carriage- way. | Loads removed in one Month. | Times swept in one month. | Gross Cost per 10,000 Yards Superficial for each cleansing. | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Yds. supr. | £ | s. | d. | ||||||||||||
| Lord Street | - | Granite setts, asphalte joints | - | 1877 | Very good | 4,503 | 15 | 26 | 0 | 6 | 5 | ¹⁄₂ | |||
| North John Street | - | Ditto | - | 1872 | Good | 3,287 | 17 | ¹⁄₂ | 26 | 0 | 8 | 10 | ¹⁄₂ | ||
| Tithebarn Street | - | Granite setts, ordinary joints | - | 1872 and 1874 | Bad | 5,150 | 38 | 26 | 0 | 11 | 2 | ||||
| West Derby Road | - | Ditto, asphalte joints | - | 1876 | Very good | 11,980 | 35 | 13 | 0 | 9 | 4 | ³⁄₄ | |||
| Great Howard Street | - | Ditto | - | 1877 | Good | 16,860 | 85 | 13 | 0 | 14 | 4 | ¹⁄₂ | |||
| Great Homer Street | - | Ditto, ordinary joints | - | Not ascertain- able | Moderate | 15,900 | 85 | 13 | 0 | 14 | 1 | ||||
| Kensington Street | - | Macadam breasted with setts | - | Ditto | Good | 14,540 | 76 | 13 | 0 | 14 | 3 | ³⁄₄ | |||
| Stanley Road | - | Ditto | - | Ditto | Bad | 16,534 | 186 | 13 | 1 | 8 | 9 | ¹⁄₄ | |||
He adds that the full benefit of the impervious pavements as regards the cost of scavenging has not yet been felt, for almost all the lines of streets so paved are intersected at short distances by streets of ordinary jointed granite setts or macadam, whence a quantity of mud and refuse is dragged by the traffic on to the asphalted jointed roadways, which are consequently debited with the cost of removal of some effete material not intrinsically belonging to them.
Mr. Till, the Borough Surveyor of Birmingham, from investigations he has made on this subject, says that for granite pavement 2 cart loads of mud have to be removed from every 1000 square yards of surface, one third of a load for wood pavement[167] and 4 loads three times a day (a total of 12 loads) for macadamised roadways.
The ultimate disposal of the material removed from the surfaces of roadways especially when they are macadamised is a difficult matter, as, being chiefly composed of silicate, it is valueless as a manure.
In small towns, except during abnormally muddy weather, it may be mixed with the house refuse and sold to farmers, or the road scrapings themselves may be used as an excellent sand, if thoroughly washed, to mix with lime or cement to form mortar for public works; excessive accumulations of mud, however, must be got rid of in the most economical and speedy manner possible, and this is effected either by filling up old disused quarries with it, or depositing it upon waste lands, or forming embankments for new roads, but in no case should it be used, as I have before stated, upon building sites; it is difficult and expensive to destroy it or partially convert it into other matters by fire, so that if these methods which I have enumerated are impracticable, the only other method left for the disposal of the sweepings or scrapings from the streets is to take them out to sea in hopper barges and sink them in deep water.