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ment is used, if the persons or load carried be different or differently distributed.
In addition, there are also three dials, for registering the distance passed over. There is also a lever, by moving which a pin is forced into the paper, to enable the observer to mark the commencement or termination of any given distance, or the situation of any remarkable object on the road that he may wish to register. By means of another lever, the cylinders giving motion to the paper are thrown out of gear, and the instrument can travel without moving the paper. A very beautiful contrivance, designed by Mr. Renton, disengages the paper the moment each sheet is completed, without any attention on the part of the observer.
There are several other arrangements in the instrument different from the first one; but without a drawing it would be impossible to describe them to a general reader.
REPORT RESPECTING THE STREET PAVEMENTS, ETC. OF THE PARISH OF ST. GEORGE, HANOVER SQUARE.
1. PRESENT STATE.
In consequence of an application to me by the Pavement Committee of the inhabitants of this extensive parish, I examined the present state of the carriage-way and footpath pavements, and endeavoured to learn the various circumstances connected therewith; I also made observations on the nature of the bottoming and shape of the stones.
The notorious imperfection of the carriage-way pavement having been the cause of this Report, it is needless to state that the surface is generally very uneven, and not unfrequently sunk into holes, so as to render it not only incommodious but dangerous to horses and wheel carriages.
The causes of this imperfection are various, and of an extensive and serious nature.
The stones, though generally of a tolerably good quality, are so irregular in their shape, that even their surfaces do not fit; they almost universally leave wide joints, and, instead of these joints being dressed square down from the surface, that is, at right angles with the face, they more frequently come only in contact near the upper edges, and, by tapering downward, in a wedge-like form, have their lower ends very narrow and irregular, leaving scarcely any flat base to bear weight.
This form also unavoidably leaves a great portion of space between the stones, which the workmen fill with loose mould or other soft matter of which the bed or subsoil is composed.
Another great defect is caused by inattention to selecting and arranging the size of stones; they are but too commonly so mixed, that large and small surfaces are placed alongside of each other, and, acting unequally in support of pressure, create a continual jolting in wheel carriages, which, adding percussion to weight, is a powerful and destructive agent.
1 must add to these defects another of an equally serious nature, that is, the imperfection of the bed on which the stones are placed.
This bed has, hitherto, but too generally been formed of very loose matter, easily convertible into mud; and this matter, instead of being compressed by artificial means, has unavoidably been loosened by a sharp-pointed instrument, to suit the irregular depth and narrow bottoms, and to fill the chasms between the joints of the paving-stones. From the width and irregularity of the joints, water easily sinks into, and converts the beforementioned soft matter into mud, which, by the continual and violent action of carriage-wheels, is worked upon the surface, and leaves the stones unsupported.
This operation must be very evident to every person who reflects upon the sudden accumulation of mud upon the surface of the carriage-way pavement after a light rain, &c, or a continuance of soft weather.
This accumulation of the before-mentioned defects has, by degrees, arisen from carrying (perhaps well intentioned) economy to much too great an extent, and which has been accomplished by the easiest of all means, that is, promoting too indiscriminate a competition, and thereby reducing the price so unreasonably low, as to oblige contractors to procure inferior materials, and prevent them from bestowing the necessary portion of labour upon dressing and setting them.
There is a defect also respecting the management of contracts, in so far as to proceed by the almost unavoidable, and hitherto unchecked, mode of performing the work by the square yard of certain depths (say nine inches). Now, as I understand that the paving-stones are .usually purchased by the contractors by weight, the more imperfect the shape is, the more profit he will have upon the superficial yard, which unavoidably must consist of a very considerable portion of loamy material, which is soon converted into mud.
The mode of repairing the carriage-way, if I am rightly informed, is equally imperfect, and has, no doubt, in a considerable degree, also arisen from the gradual introduction of low prices for repairing with old stones, by the square yard, however frequently repeated. This naturally produces hasty and imperfect workmanship.
The streets have likewise, of late years, been greatly disturbed by the laying down and repairing of waterpipes, &c. &c.
2. PROPOSED MODES OF CONSTRUCTING MORE PERFECT STREET CARRIAGE-WAYS.
The foregoing statement renders it sufficiently evident that the carriage-way pavements of the metropolis have reached a degree of imperfection which urgently demands reformation.
The defects having, however, been fairly stated, will assist us in discovering the best means of remedying them.
The result of the foregoing investigation undeniably is, that the surface of the carriage-ways of the streets is generally very uneven, not unfrequently dangerously rugged, and in constant need of repairs, and these combined circumstances have created strong prejudices against pavements.
Sundry modes have been proposed to get rid of these very general and well-founded complaints, which I shall now proceed to discuss.
One of the boldest of these projects has not only been proposed, but actually, to a certain extent, put in practice, by making a total change from a pavement surface to that of small broken stones. This radical change appearing to me to require all the judgment and experience which can be brought to bear upon it, I have not only exerted myself personally to acquire information, but have submitted the subject to repeated discussions at sittings of the Civil Engineers' Institution, when numerously attended by many of the ablest and most experienced engineers and surveyors, not only of the metropolis, but of various parts of the kingdom.
The result of these able and very candid discussions was, an unanimous resolution that whin or granite pavement, of proper form and depth, laid on a sound bottom, is preferable to any other mode for carriage-ways for the metropolis and other large cities, in order to form a body of strength adequate to bear the pressure and shocks of innumerable carriages, many of them conveying several tons.
The chief objections advanced to small broken stone were as follows: — that they cannot resist the pressure caused by a very great intercourse, being liable to be thereby crushed and ground into dust, easily converted into mud; that this hasty and continual destruction and renewal would, in a great city, prove intolerably troublesome and expensive, while the dust in dry weather, and the mud in wet, would greatly incommode the intercourse in the streets, also private dwellings and public shops. Cases were instanced where absolute nuisances had been created by employing broken stones; and that it was well known that, in some large cities, the want of pavements led to accumulations of filth, very injurious to the health of the inhabitants. It was observed, as a constant and