JF Ptak Science Books Post 2753
This is an extremely early engineering drawing of a modern propeller, executed only a dozen years or so after the creation of the modern screw propeller by John Ericsson. Shearman’s creation is devoid of the extra blades that appeared on the edges of the fans of Ericsson’s first attempts, and as ultimately adopted as the standard response to this knotty fluid dynamics problem. The propeller pictured here was for the USS San Jacinto1, a mail packet that ran along the west coast in the 1850s until it was sunk operating as a blockade runner for the Confederate States in 1864. It was a pretty large propeller–more than 15 feet in diameter–and moved the ship it was attached to more than 22 feet for every revolution of the blade.
