6 TECHNOLOGY. 
deposit is at a distance, the full boxes may be left and afterwards carried 
off together in a frame-cart. Through the bottom of « passes a pipe, the 
upper end of which reaches a little above the top of the full load of solid 
dirt; in the cart the fluid and solid parts will separate, and the former may 
be drained off into the sewers by opening the bottom of the pipe. 
At the top of the back part of the cart there is an axle movable in fixed | 
bearings, carrying two pulleys, p, of 1 foot diameter, at a distance of 3 feet 
4 inches apart ; outside of these pulleys movable about the ends of the axle 
are two light wrought-iron frames, which carry at their lower ends the 
bearings for another axle, on which also two pulleys, 5, are fixed. Round 
the pulleys p and E pass two parallel endless chains, F, on which are fixed, 
at regular intervals, thirty rows of brooms, 3 feet 4 inches inlength. On the 
top of the frame is a light cover of sheet-iron; below is a wide trough rest- 
ing with its upper end on the top edge of the lower cart-box. On the axle 
p there is finally a pinion into which works a large cog-wheel on the inner 
face of one of the cart-wheels; and thus when the cart is drawn by the 
horses the system of brooms is made to move in the direction of the arrows, 
each broom successively touching the street and carrying the dirt up the 
trough into the box. When the lower box is to be changed, or the full cart 
is to be drawn away, the whole broom-frame is raised into a horizontal 
position. For this purpose it is provided with the sector, 1, over which 
passes a chain that winds up on the pulley #; the latter is also moved by 
a crank, endless screw, and cog-wheel. On the axle of u is another pulley, 
over which also passes a chain, to the end of which weights may be applied 
in order partially to balance the weight of the broom-frames, and thus to 
regulate the pressure used in sweeping. An apparatus for counting the 
revolutions may also be attached to the axle, which is advantageous when 
the work is contracted for by the square yard. 
B. Roads. 
Roads connecting places of importance, and forming the great arteries 
of the country through which they pass, are constructed with great care ; 
they are regularly graded, drained, secured from inundation, and covered 
with gravel or broken stone, so as to be easily and safely travelled at all 
seasons. 
The grade of a road, ¢. ¢. its inclination to the horizon, should in no 
place be so steep as to require heavy wagons to take additional teams, or 
in descending to lock their wheels; it should not exceed 3-5 per cent. 
The road should be sufficiently wide to allow two wagons to pass each 
other conveniently without encroaching upon the foot-way ; the width of 
the roadway should therefore be at least 24 feet. In regions subject to 
inundation, safety requires that the road should be above the level of the 
highest water, and guarded against its pressure by bridges and break- 
waters. In order to allow the rain-water to run off rapidly, a transverse 
convexity is given to the road-way, efi m (pl. 1, jigs. 1 and 2); the foot- 
‘paths de and mn should also have a slight lateral slope towards the side- 
‘channels. The depth of the latter is 3-4 feet, and when the road is on a 
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