TRANSACTIONS OF THE SECTIONS. 129 












































work will be actuated until the going-weight be run down, to prevent which 
taking place, the influx and efflux of the tide are, by means of the following mecha- 
nism, made to rewind the going-weight. Loose on the second shaft are two 
other chain-wheels, provided with clicks, which take alternately into ratchet-wheels 
fast on the shaft. Over one of the last-mentioned chain-wheels a chain is passed, 
which, after passing under a pulley on a stud in the framing, is passed over the 
other chain-wheel, so that both ends of the chain hang on the same side of the shaft. 
To one end of the chain a weight is suspended, heavy enough to wind the going- 
weight before referred to; to the other end of the chain a hollow weight is attached, 
which is heavy enough to wind its counter-weight and the going-weight. The 
hollow weight is suspended in a tank, with which the tide has free ingress and 
egress, except as hereinafter explained. 
The action of the apparatus is thus :—On the flow of the tide the water rises in 
the hollow tank and buoys up the hollow weight, which operation allows the weight 
at the other end of the chain to descend, and that weight, by means of the chain- 
wheel (No. 3) and ratchet-wheel and click above referred to, turns the second shaft 
and chain-wheel (No. 2), and thereby winds the going-weight. With the efflux 
of the tide, the hollow weight descends and rewinds its counter-weight, and at the 
Same time, by means of the chain-wheel (No. 4) and ratchet-wheel and click, turns 
the second shaft, which again rewinds the going-weight by means of the chain- 
wheel (No. 2). 
As during the descent of the going-weight and ascent of the counter-weight, the 
length, and consequently weight, of the chain actuating the clockwork continually 
varies, another chain of equal weight per foot is attached, by its extremities, to the 
g0ing- and counter-weights, below which it extends, beyond the range of the weights ; 
consequently, as the going- and counter-weights descend or ascend, the weight of 
chain is diminished as much at one end of the weights as it is increased at the other ; 
by which means the effect of the apparatus is rendered equimotive. 
As the level of high- and low-water will vary considerably at different seasons, it 
is evident that some limitation of the height to which spring tides would raise the 
going-weight must be effected, insomuch as, unless this were done, the ebbing of 
_ those tides would cause it to be overwound, and the machinery damaged. To pre- 
vent which the action of the winding apparatus is limited thus: on the orifice through 
which communication is made between the tide and the water in the tank, a valve 
_ Opening inwardly is placed, which is connected by a cord or chain to one arm of a 
lever, whose fulcrum is above the tank, and on the other arm of which a weight, 
just sufficient to keep the valve open, is placed; the weighted arm of the lever is 
then attached, by means of a cord (or chain) to the lower end of the going-weight, 
the length of the cord being adjusted to cause the going-weight to lift the weighted 
arm of the lever and close the valve before the ebbing tide overwinds the going- 
weight, the descent of which, by the going of the clock or other mechanism, will 
_ open the valve previous to the returning flow of the tide. 
On the Superiority of Macadamized Roads for Streets of large Towns. 
By J. Picorr Smiru, Birmingham. 
There is a prevalent feeling against the employment of broken stone roads for 
streets, because, as they are usually managed, they are the cause of great inconve- 
 nience to householders and others by the dirt and dust they occasion, and also be- 
_ cause their maintenance and repairs are very expensive, while the draught of vehicles 
upon them is very heavy. The object of this paper is to prove, from long-continued 
“experience on a large scale, that those objections do not necessarily accompany the 
use of such roads. In discussing this question the interests of two parties must be 
considered: those who principally use the road,—the owners and employers of 
orses and vehicles,—and those who pay for it,—the rate-payers, the parties who 
would be injured and annoyed if it were unduly expensive or unnecessarily dirty, 
dusty and noisy. It is a common error to consider that road the cheapest which 
‘costs the least in direct expenditure. If, however, this so-called cheapest road causes 
waste of horse-power, undue wear and tear of horses and vehicles, loss of time by 
being unfit for rapid transit, and occasions loss to the inhabitants by filling their 
1849, 
