3 August, 1831.
which is consumed, that would be 70 gallons, a gallon weighing about 10 lbs, making 700lbs., the mean of this will give the quantity. If the roads are good at it does not take so much, we can do with almost half the quantity; if the roads are bad we must take the whole quantity, and the mean will be 350 lbs.
Will you state the progressive alterations you have made in the diameter of your wheel, and the breadth of the tire?—The diameter of the wheel has generally been the same, about five feet.
What difference is there between the fore and bind wheels?—About a foot in diameter difference; about the proportion of an ordinary carriage. The power is attached to the hind wheels?—To the hind wheels only.
Do the wheels follow in the same track?—That is a matter of option.
The Committee understand that they do not in that which travels between Cheltenham and Gloucester?—Perhaps that is the case there; it is a matter of convenience in some experiments; I have built them with three wheels only, one wheel in front, and in some, as in No. 3, with six wheels, my present Carriage has only four.
Do the hind wheels of your present Carriage follow in the same track with the fore wheels?—Yes; those Carriages now building will do so; the hind wheels will be nearer to each other than in many others.
What diameter do you propose to make the propelling wheels of your new Carriages?—I propose to have them about five feet; I would observe, that by taking a wheel of five feet diameter off the axle, and putting on one of two feet six, the engine would be multiplied double in its power, and lose of course one half in speed; in some cases it may be desirable to do so if the Carriages are used for general purposes; for speed and dragging of heavy weights alternately, larger or smaller wheels may be put to meet circumstances as they occur.
From the experiments you have made, with a view to proportion the diameter of the wheels with the
