An exercise in futility

This blog usually deals with medical matters; but I couldn’t resist reproducing this article from the first number of the American Medical and Philosophical Register, published in 1814, even though it was contributed to the non-medical section of the journal. An engineer called James Sharples – holder of a patent relating to steam engines – contributed an essay about the possibility of a steam-driven carriage:

There is no mechanical project, except the perpetual motion, that has been so often and so unsuccessfully attempted, as the self-moving carriage, or carriage to go by means of some internal power borne along with it; and I believe there is no engine of this kind in use, except the Bath chair, by which gouty persons can move themselves about from place to place, upon level ground, with a slow motion.

Some attempts have been made to give motion to carriages by means of steam; but none ever promised more than the one made by Mr. Trivithick, who invented an engine to act with steam of so high a temperature, as to preclude the necessity of using the condensing apparatus and air-pump. Having got rid of these incumbrances, he was confident of success. A carriage was constructed for the purpose, every thing was well contrived, and as the inventor was a man of acknowledged abilities and ingenuity, it was generally believed he would succeed; but as I had been led into much reflection on this subject by some projects of my own, made no hesitation to predict its failure to some mechanical philosophers of high repute in England, who strenuously combated the reasonings and theorems which occasioned me to pronounce so decidedly; hence I am inclined to believe, that a strict investigation of this subject has not appeared in any book of natural philosophy, and if I should be fortunate enough to throw any new light upon it, I shall please myself with the reflection that I may be the means of preventing ingenious men of ardent minds from squandering their property, or ruining themselves by so wild a project.

So far, so pessimistic.  But Mr Sharples was not acting on gut instinct: he believed his calculations proved that the dream of a steam carriage was unrealistic.  He goes into tedious length to explain his reasoning:

Let it be required to draw the carriage wheel up the inclined plane P L, by means of any power or weight W suspended by a chain coiled round the ratchet wheel. If the power W will descend by rolling the carriage wheel up the ascent, the descending line of its power must hang beyond the centre of motion on that side which would have a tendency to raise the carriage wheel, and it would consequently have some mechanical force. But to demonstrate that the wheel will not descend, let P L be drawn perpendicular to the radius B D, and let the length B D be set off from D to L, it is evident that the wheel, in rolling from D to L, will apply as much of its circumference on the inclined plane as is equal to D L or D B…

That’s quite enough of that. He applies his mechanical knowledge to the subject for several pages.  The result: forget it Henry Ford, these things will never work.

To conclude; in whatever point of view we place this subject, we shall be more and more convinced of its futility.