TRANSACTIONS OF THE SECTIONS. 131 































_ weather, which preserves the road as well as prevents the annoyance of dust. The 
practice so common in London and elsewhere of heavy watering a dirty road with- 
out cleansing it, and thereby converting the dust into mud, is very injurious to the 
road, and merely changes one nuisance into another,—dust into mud. A great 
source of waste, both to those who use and to those who repair a road, is to allow 
it to be dirty. The draught on a dirty road is twice as heavy as on a clean one, 
that is, a horse must exert double force to draw his load with the same speed. \The 
cost, however, of employing double force is so great, that the expedient of diminish- 
ing the speed is generally adopted, as a horse can exert greater pulling force at a 
slower pace,—less power being required to carry his own body. It often happens 
that the extra resistance occasioned by dirt diminishes the speed one-fifth or one- 
fourth. The effect of the dirt, therefore, is to increase the work by twenty or twenty- 
five per cent. It will easily be believed that such a waste far exceeds the cost of the 
most perfect cleansing. This is the case when cleansing is done by scrapers (the 
greatest enemy a macadamized road has to contend against). By their use the stones 
are dragged from their places, and the adhesive dirt is not effectually taken away. 
Sweeping is the only mode of cleansing that should be allowed, either on streets or 
on turnpike roads. Sweeping by the wide brooms of Mr. Whitworth’s machine is 
preferable to all other modes of cleansing yet tried. It must be evident, that the 
fact of these wide brooms sweeping longitudinally, with a pressure that can be ad- 
justed according to circumstances, tends powerfully to preserve the road and to con- 
solidate its surface. They press most upon the ridges, and least upon the hollows, 
thus tending to reduce the former, and fill up the latter. When the dirt is stiff and 
adheres firmly to the stones, it should first be well-watered, when it may be com- 
pletely removed by the machine, without disturbing the crust, leaving the surface 
firm and compact. The use of water for this purpose has been objected to by high 
authorities, on the ground that it does remove the useful grit; but the contrary has 
been proved by ample experience. I have found that the use of the sweeping- 
machines, with the proper employment of water, has reduced the amount of mate- 
rial required for the repair of roads in Birmingham one-third, namely, from about 
20,000 to 13,000 cubic yards. The first-named amount is the average for seven 
years preceding the introduction of the machines, the latter of the three years sub- 
sequent. I communicated these details to a friend in London, and he determined to 
test their correctness. The following is the result of his experiment, to settle whe- 
ther useful grit was or was not removed by water and machine-sweeping. On the 
22nd of March last, the Quadrant, Regent Street, was covered with a thick layer of 
- dirt, which was causing great annoyance as well as injury to the road, but could 
not be removed by scraping without removing also much of the new stone, to which 
it adhered. It-was determined to sweep half of it dry, and half after proper water- 
ing. This was done, and the sweepings removed were washed, to separate the refuse 
from the stony matter mingled with it. One-third part of that which was taken 
dry consisted of coarse grit, which would have been useful on the road ; one-twelfth 
part only of that which was removed in the form of slop was stony matter; and 
that was so completely pulverized as to be of scarcely any use; it had done its 
work. After the two portions of the road had been cleansed, the difference between 
them was very striking. That which was swept dry was still covered with adhesive 
matter, which was lifted by the wheels, together with the stones to which it ad- 
_hered, the whole road being rough and uneven; the portion which had been swept , 
with water was perfectly even and smooth. On the 24th both portions were swept, 
but only one quarter as much dirt was taken from that which had been water-swept 
as from the other. On the 26th it rained, and three times as much slop was taken 
off the part of the road which had not been water swept on the 22nd. The preser- 
vative effect of water machine-sweeping was most evident by the decidedly better 
condition of that portion of the road cleansed in this effective manner. The great 
objection urged against macadamized roads for streets is the annoyance by dust and 
‘dirt which they occasion, and many persons prefer submitting to the deafening 
Noise of pavement in order to avoid these; but this would not be the case if water 
and machine-cleansing was adopted, the cost of which would be saved in diminished 
‘wear and tear. ‘The entire cost of cleansing and watering Birmingham is about 
5000/. per annum, or about one penny per week for each house, or half a farthing 
g* 
