Thomas Jefferson Papers

To Thomas Jefferson from James B. Pleasants, 5 May 1790

From James B. Pleasants

Baltimore May 5th. 1790


As soon as the power of Granting Patents is vested by Law in the President, Angelheart Cruse intends to make application for Exclusive rights to a machine invented by me some years since, and for which he has my leave to take a Patent in his own name. The object in [vi]ew is to apply Liquid force, as is apprehended, [wi]th more simplicity, and superior power, [th]an has hitherto been done; particularly [st]eam, Water, and Air.—A perpetual Cylinder, mooving on the exterior of a piston with equal and Continual force, constitute [o]ne of the Essential principles of this machine, and one of its great advantages, arises from the immediate Communication of force (without the intervention of Cogg’s, Rounds or any other Machinery) to Millstones or wheels of any kind whatever. In communicating the force of Steam, this Machine will appear in the most superior point of view in which it probably can be placed; the Cylinder revolving round its axis, which is also the Axis of the Millstones or wheels employ’d to apply the force: in a Common Steam Engine the force is communicated by the recuring movement of a Piston; in this, the continual revolution of the Cylinder itself around the axis, the piston being stationary; the Cylinder in this Machine mooves with the same force that the piston in a common Engine does, multiplied by any number that we please under 25; the difficulty arising from the complexity of machinery necessary in applying a recuring force to Wheels is remoov’d. This difficulty is Threefold. 1. Expence 2. friction 3. the loss of force apply’d to a Crab.

I know no better appology for this Sir than the cause. I have observ’d an application (mention’d by the publishers of the debates of Congress) made to that body for an exclusive right to the use of perpetual Steam, if it is the same with mine, the priority, and superiority, will be questions that appear to justify the foregoing explanation of the principle my Machine Acts upon. I have confined myself in the foregoing Explanation to general principles. The particular machine will be best Explained by a model that will be presented by the applicant for a Patent. I am with the highest sentiments of Respect

James B. Pleasants

RC (DNA: RG 59, MLR). Recorded in SJL as received 3 June 1790.

The “scollership as it Regards … Riting” of Englehart Cruse caused both him and his correspondents to spell his name in various ways (Cruse to TJ, 3 July 1813; TJ to Cruse, 23 July 1813). James McHenry introduced him to TJ in these words: “Mr. Englegard Cruze … is an ingenious mechanician of this town who has made certain improvements in steam engines for which he is desirous to get a patent. His scientific attainments are not many, but his natural powers very considerable. I take the liberty on account of the latter to mention him to you, that you may see what our soil is capable of producing without the help of culture” (McHenry to TJ, 18 Apr. 1791; endorsed as received 22 Apr. 1791 and so recorded in SJL; DNA: RG 59, MLR). It was evidently some time before this that the inventor, signing himself “Angelhart Cruse,” presented an undated application to Washington for “an Institution” and enclosing the plan of his steam engine, claiming it to be of great utility and hoping its performance might be viewed, as it had been by “many Respectful Characters” in Baltimore (DNA: RG 59, MLR, filed under 1 Sep. 1790; see illustrations of steam engine in this volume). Cruse was issued a patent on 30 Aug. 1791 (Washington, Writings, ed. Fitzpatrick, xxxi, 352 n.). The rights were assigned to “Englebert Cruse” (Lear to TJ, 30 Aug. 1791; see also Pleasants to TJ, 6 Aug. 1790).

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