During this jumble of engines, old and new, without a clear comprehension of their differences in principle, Trevithick, who had just returned from America, and lived within a few miles of Wheal Towan, looked on unconsulted and unconcerned on questions which in his mind had been settled by him in Dolcoath fifteen or twenty years before. The writer, during the Wheal Towan controversy, was the daily companion of Trevithick, and made drawings of the engine at the works of Harvey and Co., of Hayle, where it was constructed about 1827. Captain Samuel Grose's Wheal Towan engine was in general character similar to his teacher's Dolcoath 76-inch engine of 1816, working with about the same steam pressure and degree of expansion. The valves, gear, and nozzles were perhaps improved in detail; but the groundwork was unchanged. The first high-pressure steam Cornish pumping engine made in France was designed and superintended by the writer at the works of Messrs. Perrier, Edwards, and Chaper, at Pompe-à-feu, in Chaillot, a suburb of Paris. The principle was the same as the Dolcoath engine, and the detail differed but little from it or the Wheal Towan, except that its exterior was a little more artistic than its prototypes in Cornwall, in keeping with French requirements. It was built in 1836, within a few yards of the low-pressure steam pumping engine erected by Perrier and others in 1779, which still continued pumping water from the Seine for the supply of Paris. Stuart says, "An engine by Boulton and Watt was sent to France, and erected by M. Perrier at Chaillot, near Paris. The French engineer, Proney, with a detestable illiberality, attributes all the merit of the improvements in the Chaillot engine to his friend Perrier, the person who merely put together the pieces he had brought from Soho."[117] [Footnote 117: Stuart 'On the Steam-Engine,' p. 141.] The Perrier of 1779 was related to the Perrier of the Pompe-à-feu engine-building works of 1836, and his nephew took the Trevithick engine from Paris to a coal mine not far from Brussels, but not fully understanding the use of the balance-bob--the woodwork for which had not been completed in Paris, though all other parts had been fully erected--did not find it easy to manage the engine. The writer viewed Perrier's move as an infringement of the agreement between him and Edwards, the partner of Perrier and Chaper, and therefore declined to take any further interest in the engine. Mr. Edwards had before that been a partner with Woolf, in a small engineering works in Lambeth; and the writer had also before that been a pupil of Woolf's, in the works of Messrs. Harvey and Co., of Hayle.