Note 228 — Chapter XV · Watt again visits Cornwall—Invention of the Rotary Motion—The Patent Right again assailed.

Boulton to Watt, 10th September, 1781. Boulton immediately proceeded with the erection of the new engine as secretly as possible. “The principles of the expansion engine,” said he to Watt, “you had invented before Dr. Small died, as Mr. Keir can testify as well as others. However, it is highly proper to execute every kind of beam that can be devised for the purpose of equalising the power. I have removed the little portions into the wooden house next the smith’s shop, and have blinded the window and barred the door. There is a convenient well that can be filled from the back brook, and the engine may be applied to the raising of water, which is the best sort of load to calculate from.”