Mr. Nathaniel Ogle.
17 August, 1831.
legraph from London to Southampton, with its full load, has been reported to me, by its proprietors, to weigh about three tons.
What would be the weight of your machine when loaded?—Three tons beside its load.
What do you suppose the nineteen passengers weighed?—A ton and a half certainly.
The breadth of your tire is three inches?—Yes.
From your observation of the effect of a Coach weighing three tons, and a two and a quarter inch tire, going along a road, seeing the impression made upon the roads, and witnessing your own Carriage, weighing four tons and a half, with a three-inch tire, what is the relative indentation or injury done to the road?—Not greater as far as I have ever been able to observe.
Is it as great?—I think not as great.
Independent entirely of the injury that the four horses do to the road?—Just so. Independent of that entirely.
Can you suggest any mode by which Tolls shall be fairly charged on Steam Carriages?—I should say by their weight, with a deduction in favour of the Steam Engines, inasmuch as they do not the same degree of injury to the road as a vehicle drawn by horses.
Do you think that the injury done by four horses on a road is greater than the injury done by the four wheels of the same Carriage?—Decidedly.
Upon what data do you state that opinion?—Because the animal must hold on as he goes, if he has a great weight behind him he must hold tighter than if he merely carries his own weight; I do not know the number of strokes that a horse's foot must have gone in an hour, but it is a great number, and where there are four horses those must be multiplied, and this on a road moistened by the rain must make great indentations and tear up the surface, the transit being continuous, the road must suffer more than from the mere pressure of the tire over it.
Do you state that as your opinion merely, or as the result of your observation and practice?—As the re-
