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abundant supply of broken stones would be required for repairs always hastily performed while the streets were empty, that receptacles, such as made in country roads, would not readily be found in London, where space is so valuable and so fully occupied. And it was further observed, that a surface of broken stones frequently covered with dust and mud was more injurious to the feet of horses than a properly constructed pavement, which is also much easier for their labour. And, lastly, that the expense of making and maintaining a street carriage-way with broken stones, including the constant labour and carting away scrapings to different depositaries, would be at least fifty per cent, more than by a proper pavement.
These observations corresponding with my own sentiments and experience, I am led to recommend pavement in preference to broken stones for the carriage-way of the streets in St. George's parish.
3. OF THE BEST MODE OF CONSTRUCTING PAVEMENTS.
To obtain a smooth and durable pavement surface, the following essential matters must be attended to: —
1st. The bed, or bottoming upon which the stones are to be placed.
2dly. The quality, size, and shape of the stones.
3dly. The mode of contract for constructing and keeping the pavement in a state of repair.
After the space between the foot pavements has been brought into a form, consisting of a very slight curve in the cross section, every devisable means should be resorted to in order to render it compact and solid. Where practicable, it will be advisable to have wheel carriages to run for some time over it, or, occasionally, water; or to use the roller and stamper. These operations performed, it is necessary to cover the whole surface with a stratum, or layer, of some sort of substance, which will effectually cut off all connection between the subsoil and bottom of the paving-stones. This must itself be indissoluble in water, and prevent any of the substratum from rising in the shape of mud. Where stone can be cheaply procured, a bed of it, broken very small, would perfectly answer the purpose; and hence it has been observed, that the present broken stone experiments, in certain streets, will not be an entire loss, because they will, at all rates, constitute a good bed for a proper pavement. But, as relates to the metropolis generally, I am persuaded that a bed of cleansed river ballast, about six inches in thickness upon an average, will be found to answer the purpose, and is to be obtained at a comparatively moderate expense.* This should also be rendered compact and solid; it might be travelled upon for some time without inconveniency, particularly in summer, being the season when paving is usually performed.
2. Quality, Size, and Shape of Stones.
The qualities of the granites hitherto used are not so materially different as to require much discussion; but as there are differences in stones from all quarters, the judgment of the surveyor, who has charge of the works, and is supposed qualified, ought to be constantly exercised to ensure a due fulfilment of the contract in regard to the materials. I have understood diat by former and recent experiments, the Guernsey stone is of great compactness and durability. This deserves attention and a fair and impartial trial. The only objection I foresee, is in its disposition to smoothness of surface.
• On reconsidering this subject, I am of opinion that this quantity of ballast will not make a sufficiently strong bottoming, and that nothing short of twelve inches of broken stones, put on in layers of four inches each, and then completely consolidated by carriages passing over them, will answer the purpose T. Telford, July 18, 1833.
With regard to size, it ought to be regulated, in some measure, by the nature and quantity of the intercourse through the several streets: they may be conveniently divided into three classes. For streets of the first class, or greatest thoroughfare, the stones should be not less than ten inches in depth, from eleven to thirteen inches in length, and from six to seven inches and a half in breadth on the face.
For the streets of the second class, the stones should not be less than nine inches in depth, from nine to twelve inches in length, and five to seven inches in breadth on the face.
For the streets of the third class, the stones to be not less than seven to eight inches in depth, from seven to eleven inches in length, and four and a half to six inches in breadth on the face. Crossings ten to twelve inches in length, seven to eight inches in breadth; the depth to be according to the classes.
All these stones to be worked flat on the face, and straight and square on all the sides, so as to joint close, and preserve the bed or base, as nearly as practicable, of an equal size to the face; and stones of equal breadth on the face, must be carefully placed adjacent to one another. The inferior streets, mews, and passages may be paved with the inferior stones from the other three classes, and those stones unfit for any pavement may be usefully employed by being broken small, as bottoming for the pavement of the first class of streets.
With regard to the shape of the stones, those modes I have hitherto been considering have been supposed rectangular, with joints made exactly to fit close to each other, and which, if perfectly executed, taking into consideration all the angles, the strongest possible, and also the most simple, whether we regard the preparation in quarrying and dressing, or the practical operations on the streets— right angles admitting of a variety of size, but always fitting, however applied, and, of course, under all these circumstances, the cheapest.
3. Modes of Contract, &fc.
In constructing new pavements by the present practice, I have already stated, that it is the interest of the contractor to work with stones of a defective shape. The making the superficial yard of face-work must, I conceive, still be continued as the rule; but, along with that, weight ought certainly to be combined, as a proof that the quantity of stone intended is really obtained; the shape of the stones must be accurately defined in a specification, and, above all, the surveyor or inspector must, by unremitting attention, see that every part of the contract is fully and faithfully performed. A further security for the perfection of the work would be obtained by making it a part of the agreement, that the contractor should keep the work in a perfect state of repair, at a given rate per yard, for a certain number of years; the necessary repairs to be from time to time pointed out by the surveyor, under the direction of the Committee.
In repairing the streets, as far as regards the stones now in use, although these stones are, undeniably, very imperfect, yet the quantity and value being so great, no project for rashly disposing of them is admissible; but a thorough improvement may be gradually accomplished in the following manner: —
The streets to be divided into three different classes. For the first, and most important, perhaps very few of the present stones are suitable; if there should be any, they may be reworked and replaced, and new stones of a proper shape (of course) provided for the rest of the street. The stones rejected from the first class should be carefully sorted and reworked, for the repairs of such of the other classes as they are fit for, taking care that the stones, in all cases, are worked into proper forms, as regards the joints and bottoms; that the bottoming or bed has been formed of proper materials, not convertible into mud by the water running down the joints, and that the stones, as to sizes, have been judiciously arranged.
It is now, I understand, the mode to repair by the yard superficial, in partial spaces pointed out by the surveyor, at a price per yard for each time. The contractor, therefore, has no inducement to have the operation performed in a complete and substantial manner; but, on the contrary, it is his interest to have a great quantity done by his workmen in a short time, because, the more frequently it fails, the more demand there is for his services. I do not by this insinuate unfair practices against any individual contractor, but the practice is undeniable.
To correct this apparent evil, it seems advisable to let a whole street, or certain number of streets, for a certain time, at a fixed price per yard; the necessary repairs to be pointed out by the surveyor, under the direction of the Committee.
From what I have here stated, it must be quite evident that, to acquire a necessary degree of perfection, the most unremitting and strict attention, on the part of the surveyor, is absolutely necessary; and that St. George's extensive parish is quite sufficient to employ the whole time of the most active and persevering man. He ought to have no other object, and his remuneration should be sufficient to attach him to his duty.
But even his most judicious and faithful exertions will be unavailing, unless a price is allowed equal to the fair value of the materials and workmanship, and a reasonable profit to the contractor, as I cannot help again stating, that the injudicious practice, which has of late years very generally prevailed, of reducing prices too low, has led to the imperfect condition the street pavements are now in, and which, in works of this nature, is a very mistaken economy; for of all things, streets of great thoroughfare