A lithograph containing two separate images.
The one on the left, occupying the majority of the sheet, depicts ‘Jonathan Hull’s Steamboat’ (with paddle wheels at the stern) in port-broadside view, patented in 1736(?), towing a three-masted sailing ship (square fore and main masts, and square topsail on the mizzen mast). Inscribed below the image: ‘Jonathan Hull’s Steamboat, used as a means of Towing other Vessels out of / Harbor.’ Despite having been patented, it was probably never built.
The image on the right is a bird’s eye view of ‘Patrick Miller’s double Boat’ (stern facing north), patented in 1787. It resembles two skiffs bound together with 20 thin (presumably wooden), horizontal planks across the centre; a paddle wheel can be seen joined in between the two sterns. Miller’s patent was for propelling boats by paddle wheels turned by hand and had even suggested powering the wheels by means of a steam engine (not visible in the image).