A patent granted by the Georgia Assembly to Isaac Briggs and William Longstreet for their steam engine, 1789.

Isaac Briggs was an engineer and surveyor and William Longstreet was an inventor. They used their steam engine to power a steamboat along the Savannah River in 1807, but Robert Fulton had successfully piloted his steamboat, the Clermont, in New York several days earlier. This patent, issued by the State of Georgia, was granted before the formation of the U.S. Patent Office.


An Account Of The Construction And Principles Of Briggs' And Longstreet's Steam Engine, For The Exclusive Use Of Which A Privilege Was Granted To The Investors, For Fourteen Years, By An Act Of The Legislature Passed At Augusta, The First Day Of February, 1788.

This engine consists of a Boiler, two Cylinders and a Condenser, constructed in the following manner, viz.:

The Boiler
Consists of two metallic vessels, globular, or nearly so, placed one within the other, so as to leave a small interstice between, in which interstice the boiling water is contained. The inner vessel contains the fuel, the flame of which passes through a spiral flue winding round the outside of the outer vessel from the bottom to the top. The steam is conveyed by a pipe from the boiler into an interstice between

The Two Cylinders
Which are placed, horizontally, one within the other, from whence it is admitted alternately into each end of the inner cylinder, in which it impels a piston to vibrate both ways with equal force. It is also admitted alternately to pass from each end of the inner cylinder (all the communications, to and from which, are opened and shut by a single cock) by means of pipes into

The Condenser,
Which is a metallic vessel having a large surface in contact with cold water. The condensed steam or warm water is drawn out of it by a pump.

I. Briggs,
Wm. Longstreet.
Recorded 30th Jan. 1789.