Note 221 — Chapter XV · Watt again visits Cornwall—Invention of the Rotary Motion—The Patent Right again assailed.

Watt to Boulton, 28th July, 1781. A few days later Boulton wrote Watt that Dr. Priestley had proceeded with the experiments, and that he had come to the conclusion that “there is nothing to be feared from any of the tribe of gases, which cannot be produced nearly so cheap as steam; and as to steam you know its limits better than any man.”