ing down this cemented mass, and constructing the road, is fully detailed in the following evidence, given by Mr. M'Neill before a Select Committee of the House of Commons in May 1830:

"Are you the resident engineer under Mr. Telford, on the road from London to Shrewsbury?— Yes.

"You conducted the work at the Highgate Archway road?—I did.

Will you explain to the Committee the expense of the cement composition which was laid on the foundation ?-The expense of the cement delivered was 2s. a bushel; it was mixed with eight times as much of washed gravel and sand.

"What distance of ground would a bushel so made extend?-Laying on the cement six yards wide and six inches in thickness came to 10s. a running yard; but in this case part of the gravel got in taking up the old road was used; if new gravel had been purchased, it would have cost from 12s. to 15s.: that included the forming the bed of the road, which was done with very great care. There were four drains formed longitudinally, and there were secondary drains running from those to the side channel drains, and those again to drains outside the footpaths, covered with brick, and they all communicated with each other, and discharged the water into proper outlets. On the prepared centre of six yards in width, after it had been properly levelled, the cement was laid on, mixing it first in a box with water, gravel, and sand, in certain proportions: every cask of cement was

tried before it was allowed to be used, and when we found it set properly in about fifteen minutes we then used it.

"Did it become hard in fifteen minutes?—Yes, so that we could stand upon it: in about four minutes after being laid, a triangular piece of wood, sheeted with iron, was indented into it, so as to leave a track or channel at every four inches for the broken stones to lie and fasten in.

"For grooves for the stones to bed in?—Yes; and this triangular indent had an inclination of full two inches from the centre to the sides; so that if water came through the broken stones it ran off the cemented mass into the longitudinal drains.

"The cement had that fall from the centre of the road?—Yes, three inches from the centre to each side; that was sufficient to allow the water that percolated through the broken stones to run off.

"What time of year was this composition laid on the road?- 200 yards was done in winter; all the rest in July, August, and September.

"It has been on the road through the last winter? There has been part of it on since June 1828, nearly two years.

"Have you examined it to see what effect the weather has had on it? I examined it frequently during the frost, almost every six weeks, and I never came to town without examining it.

"In what state have you found it? - Perfectly hard in every case.

"Not injured by the frost nor the working of

the carriages over it? Not in the least: there was an injury of six feet square, but it originated from the side banks of the road coming down and bulging it up.

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By under-pressure?—Yes; only six feet square was injured.

"At what rate of expense can a square yard be laid six inches thick of this composition? In the neighbourhood of London it could be laid for about two shillings, according to the locality, per yard six inches thick.

"Was it dearer at Highgate, at the Archway Road? - About twopence dearer than it would in London.

"How many yards wide was it laid? - Six yards wide: the gravel that was found in the road was made use of for part of it; if it had to be purchased, it would have cost 2s. to 2s. 6d.

"What state was the road in when it was given into your possession by the Company?—I think it was as bad a road as I ever saw; a coachman could hardly sit on the box when driving along it.

"Was it in consequence of the surface being so uneven? - The surface was uneven in some places; it was not in ruts, but in holes several inches deep. "What was the surface composed of?-Principally clay, gravel, and sand.

"No body of strong materials?

They could not last on it; they were worn out; an immense quantity had been put on; there were 1,200 cube yards of gravel put on annually. Shortly before

we took possession of the road, they put about 800l. worth of granite on a small space; the directors said it was necessary to examine the quantity of granite in the road, that we might deduct it from the contractor's prices, as they had laid out out 8007. in so short a time; I did in consequence examine it, and opened the road in various places, particularly where they told me it was on, and I could hardly find a stone of it.

"Were not some of the stones worn into a perfect round shape ?-Almost every one I found was as round as an egg.

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What, in your opinion, was the cause of these materials wearing out so rapidly?-From the rubbing against each other, and from the weakness of the surface, and the elasticity of the road; in all cases those round stones were at the bottom.

"Was the road damp and wet?—Very wet.

"Had those stones worked themselves down below the furze and tin you say you had to remove? They were resting on them, and they were quite elastic.

"Can you state to the Committee how many tons of gravel and stone have been laid on the road since it has been put under the care of the Commissioners? - Eight thousand one hundred and forty-six tons of gravel, and 3,614 tons of granite.

"Can you state the number of yards of drains that have been made? There have been four longitudinal drains made the whole length of the road, besides numerous cross drains, one at every

thirty yards; and there have been intermediate small drains every ten yards under the cement; making in all, 12,803 yards.

"What was the reason for making such an unusual quantity of drains? - From the nature of the ground: it was cut through a clay soil, high banks on each side; and all the surface water that came from the slopes and Highgate Hill, came down and rested in the hollows of the subsoil.

"You made use of the cement because you could get no stone to make a pavement? — That was one cause; in that situation it was both better and cheaper than any stone.

"Can you give the Committee any statement of the comparative expense of keeping the road in repair previous to the undertaking of the work by Mr. Telford and since?-Yes, I can; Yes, I can; I understand it cost 900l. a year; it can now be kept in good repair for much less.

"Have you an opportunity of explaining to the Committee the different degree in which the hard stone wears where laid on the surface of such a road as that was, or laid upon a cement foundation ?— Yes, I have; I have tried it repeatedly since the stone has been laid on.

"How many inches did you find of the stone wear out which was first laid on the road before the cement bottoming?-I found four inches. gone in one place where it was not on the bottoming, and not half an inch where the bottoming was: the same stone, quartz, was used in each experiment.

M