# Report from the Select Committee on Steam Carriages/McAdam

Mr. James M$^c$Adam, called in; and Examined.
Are you Surveyor of the Holyhead line of road?—As far as St. Alban's.
Have you the superintendence of any other portion of it?—Of no other portion of it.
Have you had considerable experience in road-making, and superintending roads?—Yes, for the last fourteen years.
Have you made any experiments, or are you able to give any information to the Committee, as to the comparative wear of roads, or injury to roads by Carriages and horses passing?—I have generally found that horses' feet do very great injury to the surface of a well-made road; and I am of opinion, that a Carriage with properly-constructed wheels does less injury to a road than the horses drawing.
Would you explain what the operation of the injury done to the road is by travelling on it; is it the wear of the road, or the displacement of the materials?—Both take place; the wheels to a certain degree wear out the material, but upon a road properly constructed, and that has become consolidated, and the surface smooth, that wear is very small and gradual; ​the injury to the road from the horses' feet, more especially upon gravel and flint roads, arises particularly in dry weather from the knocking up and displacing the materials upon the surface, and each succeeding journey adds to the evil, and were it not for the effect of the wheels following the horses in mitigation of that evil, we should have the flint and gravel roads all loose throughout the whole summer.
But the wheels of the Carriage do not actually follow in the track of the horses?—But in roads of much thoroughfare, especially near the Metropolis, other Carriages do.
On the Metropolis Roads have you made any new regulations as to the mode of charging tolls by weight or otherwise?—In the last Act passed for the Metropolis Roads, the toll was put upon the horse drawings and a regulation as to the formation and breadth of the wheels expressly enacted, by which all wheels were required to be not convex, but a perfectly flat surface, with no projecting nails; but by the powers granted to the Commissioners in that Act, that perfectly flat surface was mitigated to a surface not exceeding a quarter of an inch from that flat surface, to meet the practical effect arising from the wear of the wheels upon the road; and to prevent litigation at the several gates, by applying a guage, a toll of 3d, per horse for each seven miles is payable upon a six-inch wheel so constructed; a quarter more upon a wheel so constructed of four inches and a half in breadth, and a half more upon a wheel less than four inches and a half. Those additions do not apply to Stage Coaches or Carriages with springs. The toll upon all horses drawing Carriages and Coaches with springs is 3d, a horse for seven miles, whatever may be the breadth of the tire.
You have had no reference to the weight of the Carriage drawn in your rate of the tolls?—There is no reference to the weight drawn in any Waggon or such like Carriage, provided the wheel is of the construction required by the Act, and the result of some years' experience proves that no injury whatever is sustained upon a well-made road, from any weight ​practically carried in Waggons, or such like Carriages, with wheels as described.
You do not mean that the Committee should infer weight is of no consequence, but that the power of the horse will be your guard against an overweight being drawn?—Yes; the toll being laid per horse. I consider that the penalty in the shape of toll per horse, more than compensates for the injury done by the weight. Before those regulations took place, the roads in truth sustained an equal pressure, from the well known fact that the weighing Engines were universally compounded for by all the carriers, and that the roads, after these regulations, had no greater but even less weights to sustain than before that took place, and it was observing that fact, which induced the Commissioners of the Metropolis Roads to do away with all the Weighing Engines.
Do you know whether the Holyhead Road Commissioners are trying to do away with the necessity of Weighing Engines?—Upon the Trusts, on that line of which I am Surveyor, the Trustees have done away with all the Weighing Engines, and the happy result of compelling the Waggons to set out and arrive upon the Metropolis Roads with properly constructed wheels, has had the effect of enabling the Trustees upon all the roads within a circle of fifty to eighty miles, to dispense with the Weighing Engines; also, because if the Waggons set out and arrive in the Metropolis District with a properly constructed wheel; it was not worth their while to alter it, but to travel throughout to Cambridge. Newmarket, &c, with the same wheel; and the benefit of the metropolis wheel has extended itself in consequence.
Then supposing a broad wheel waggon with dished wheels was to pass through your turnpike, what rate would be charged?—It would be charged the highest rate of a narrow-wheeled Waggon.
Have you heard any complaints from the Waggon masters of the regulation of the form of the wheel? On the contrary, a few days since we had a Petition most numerously signed by the Waggon masters from Norwich. Cambridge. Newmarket, &c., requesting ​the Trustees of the Wadesmill Road to dispense with the use of their weighing Engine, they having found by experience that the wheels required by the Metropolis. Commissioners, were not only best for the road but the most advantageous for themselves to use, and in consequence of that application, on Friday last, the only remaining Engine on the roads of which I am Surveyor, was ordered to be abandoned.
Can you state the weights of a loaded Stage Coach, and a loaded Waggon, and a loaded Van, on the average?—I should state a Stage Coach loaded, at from two and a half to three tons; a Waggon from five tons, to seven and a half.
Does that include the weight of the Waggon?—Eight tons would; I should think the weight of the Vans about four or five tons.
Have you observed the operation of wheels when they are dragged?—Yes, they are injurious upon roads newly coated certainly, but upon an old road. I mean a road that has become consolidated upon the surface, the injury, with proper skid pans is but small, and confined of course to one side of the surface of the hill.
Do you think the efficacy of your toll in protecting the road is equally applicable to a heavy Van as a loaded Coach—I think that the toll per horse will always be a sufficient guard for the weights drawn, the Van being on springs does infinitely less injury in proportion than such a weight without them.
But if the injury to the road proceeds from the weight the horses have to draw, the same rate of toll would not be applicable to a Carriage of two tons and one of six tons, both being drawn by four horses?—Certainly not; but that is a supposition hardly fair to be taken, because we conclude that the additional weight requires additional horses.
But in practice the Vans pass all through the country with only four horses, and the Coaches equally with four horses?—That is true; the Coaches go at a much more rapid pace.
Do you think that the velocity with which a Coach ​goes, has any thing to do with the wear of the road, or is it not actually less injurious in proportion to its velocity?—In some instances where any blow takes place the speed does more injury to the road by crushing the materials.
You did not contemplate the general use of Vans, when that Act was drawn up?—No; not that they would come into such general use.
What proportion of the injury to the road do you think takes place from the changes of the atmosphere; frost and wet, has it any material effect?—Yes, decidedly, in chalk soils in particular; at Royston and through that country a great and serious injury takes place upon the breaking up of all frosts, nor can we, by any care or attention or strength of surface of the road prevent that taking place; it comes in a very eccentric manner and breaks up one year at one part of the road, and another at another, occasioned in a great measure by the standing of the water in the subsoil; and I suppose also, by the way in which the wind is at the time it freezes. It is the modern practice of road making to abstain from all general repair of the roads from the middle of April until the middle of October; during that period the only repairs that ought to take place are partial coatings, necessary from accidental circumstances. As soon after the middle of October as possible the general coating takes place in pieces of the road at a time, so as to interfere and interrupt as little as possible with general travelling, and we endeavour, by the month of February, to have the whole of the coatings put on; in no instance above a sixth part at a time.
On your line the Committee find, that the course of horizontal traction varies from 42 to 140, with these remarks, in the case of 42 "granite surface of many years standing," and the 140 "smooth surface road made of broken granite;" can you explain why such a difference should take place, both being smooth surfaces?—I am quite unable to account for it; no coatings of dirt upon a granite road ought to have produced so great a difference.
Have you witnessed the operation of a Carriage ​propelled by Steam on the public roads?—I have observed it; but in a small degree.
Who was the proprietor of the Carriage you noticed?—I think it was Mr. Gurney's; I accidentally saw it.
Then you only saw it once?—Only once.
What was the state of the roads when you saw it?—Tolerably good at the time; I saw it in the Regent's Park.
Were they in such a state you could make any observation upon the greater or less injury produced by it than by a common Carriage?—I cannot say that my attention was directed at that time to that fact; I have not had an opportunity practically of seeing the effect of Steam Carriages upon roads, there have been none used near us except passing down to Virginia Water, &c.; but not being brought into general use. I have not seen sufficiently the effect of their wheels upon roads.
From the experiments you have before stated, what should you recommend should be the breadth of the tire of the wheel of a Carriage with four wheels weighing four tons?—I consider that a Carriage of any description required to carry a great weight, five or eight tons, ought to have a wheel of four inches and a half in breadth, constructed agreeably to the Clause in the Metropolis Act; and I consider that a Carriage with such a wheel, though carrying an excessive weight, would do very little injury to the road.
It has been stated by a previous Witness, that a Carriage of the weight of two tons propelled by Steam drew after it another Carriage weighing nine tons; what should, from your experience, be the breadth of the tire of the wheel of the propelling Carriage and the Carriage drawn?—Looking solely to the welfare of the road. I should prefer a wheel of four inches and a half, flat on the tire, to any other class of wheel that can be made, being of opinion that a greater breadth of wheel cannot at one time touch the surface of a well-formed turnpike road.
Then you would prescribe that breadth as the ​minimum breadth of wheel for any weight?—Yes, I do not think any increase of breadth would be of any 25 August, service.
Supposing two Carriages, cne drawn by horses, and the other propelled by Steam, the weight of the Steam Carriage being four tons, and the weight of the Carriage drawn by horses being two tons, which would do most injury to the road, provided the breadth of the wheels were the same in both cases?—I should prefer, with a proper wheel in both cases, the Steam Carriage without the horses, because that question can only be answered with reference to the wheel.
Then, in the case given, if the wheels of the Steam Carriage were four inches and a half, and the wheels of the Coach two and a half, which would do the greatest injury?—The Coach, decidedly, drawn by horses, though only two tons and a half, infinitely more; because I consider, that of all classes of thoroughfare at present, the Stage Coach, as usually la- den, does us the greatest injury.
Can you suggest any mode by which Tolls could be fairly charged on Steam Carriages, in relation to the Toils charged on Coaches?—The mode adopted in Coaches, of taking toll per horse as well as Wag- gons, has been found to answer every purpose, it be- ing, in truth, a penalty upon weight. If greater weight is put upon a Waggon, a greater number of horses are necessary to move it, and the parties bring the penalty in the shape of toll in their hands. This cannot be applied to Steam Carriages, and I am at a loss to recommend to the Committee any general mode, unless the diameter of the cylinder or power of the Engine could be taken. In the Metropolis Act of 1829, there is a toll laid upon Steam Carriages; any Carriage that shall be in any manner drawn by Steam or Gas, shall pay the toll that would be paid by any Carriage drawn by four horses.
If the power of the Engine is equal to any number of horses you only charge the same toll?—The same toll.
Then if a Steam Carriage drew another Carriage ​after it; or two Carriages after it, would it be two of three tolls, or one only?—Two or three tolls; where a Steam Carriage' conveys passengers by drawing 25 August another Coach they would each pay the toll of four horses, this is a matter still in its infancy; in many Acts, such as the Lemsford Mills Act; a toll of half-a-crown was introduced for any Carriage drawn or propelled by Steam.
Would not this inconvenience arise from the Clause you have read in the Metropolis Tolls Act; it would be-a premium given in favour of one description of Steam Carriage over another, though the injury done to the road might be in favour of the one less taxed, as in the case of a Steam Carriage carrying 20 passengers, and another Steam Carriage drawing a Carriage containing the same 20 passengers?—In that case the toll would certainly be an unjust one, and require revision; it was a point not settled and it was put in merely to commence the toll, and call the public attention to it. I beg leave to observe, that if these Carriages come into general use, they would necessarily require a still greater perfection in the surface of our roads, and also in the levelling of the remaining hills; as good surface and little inclination is to them of the greatest importance.
If that is the case, would it not be necessary to lay considerable rate of toll upon those Carriages, for the purpose of affording the means of executing those improvements?—It is found, that lowering the hills, and improving the surface of all the roads, is productive invariably of a great increase of thoroughfare; and although lowering the hills might be attended with the first expence, any excitement that would induce the Trustees of the Roads to keep them in good order, would be at the same time productive of economy, a good road being always the cheapest.
Do you not suppose, if those Carriages were in general use, the very action of the wheels upon the roads would prevent the necessity of such frequent repairs as are required at present?—I should think that the absence of the horses' feet in a great degree upon the roads, would be a very considerable saving; ​and I have already stated, that these Carriages, with properly constructed wheels, would be the class of 5 August. Carriages that would do the least injury to the roads.
What is the greatest speed you have known a Carriage drawn by horses to execute a given number of miles on your Trust?—I once, by mere accident, came in the Leeds Union Coach from Grantham, which is 110 miles from London; I got into the Coach at three o'clock, and I was in London at half after one the same morning; that was at the time the Leeds Union and the Rockingham were racing the whole way up.
Are you aware that Mr. Telford states in his Report on the state of the Holyhead Roads, that three of the Birmingham Coaches perform the journey of 110 miles in less than eight hours, without any accident, at the rate of thirteen miles and six furlongs an hour?—I have frequently beard it stated upon the road, though I do not know it of my own personal knowledge.
Have you any other observations you would wish to make to the Committee?—I am not aware of any point.
You do not think it will be necessary to limit Steam Carriages to any particular number of passengers, provided the wheels were of the dimensions stated?—If the wheels were of the dimensions and the description stated. I should, in reason, be regardless of weight, experience having completely proved, with properly constructed wheels, we sustain little or no injury from weight.
What is the maximum weight a road would bear upon each wheel?—The injury done by weight upon a road in a Carriage with proper wheels is principally. I might almost venture to say exclusively, to the new coatings; if the weight in such Carriage is a crushing weight, as applied to the materials with which the road is made, it does a very considerable injury, and therefore were Steam Carriages to become in general use, it would be a matter of great importance, that harder material should be introduced, that flint should take the place of gravel, and that granite or whinstone take the place of flint which is the principle acted ​upon by the Commissioners of the Metropolis Roads, but upon a bard and well consolidated road a very great weight may be sustained without doing comparatively any injury.
When you state that if Steam Carriages come into general use harder materials ought to be used, you suppose that these Steam Carriages will be much heavier than the Carriages used at present?—Yes; I contemplate that they will carry much greater weights.
Your answer does not apply to Carriages that are of the same weight as those now used?-No; but to Carriages of the weight of eight or ten tons; when I spoke of the weight of from eight to twelve tons. I supposed a Carriage with four wheels.
Upon the present well constructed roads what weight do you think could be put upon them without crushing them?—I should not apprehend any injurious result from the general use of Steam Carriages with properly made wheels, carrying upon an average from eight to ten tons.
Your answer refers to roads that are so well made that the whole pressure shall be as that of an arch, but on the average of roads, such as shall be found in the country, would you give the same answer?—No, certainly not.
Taking the average of any line of road for a great number of miles, where materials less capable of bearing weight must necessarily be used for a considerable proportion of that road, what should you say is the maximum weight that should be allowed with reference to the preservation of that road on any one wheel of four inches and a half?—Two tons. Have you ascertained that by experiment?-I have not had an opportunity of judging of it, except in all the Waggons that depart from the Metropolis that are required to have the wheels constructed in the way I have described, some of which carry considerable weights.