In particular I am interested in #8 John Hancock. This locomotive is shown as a “Crab” in the 1848 & 1860 annual reports. All current accounts show it to be the Grasshopper on display at the B&O museum. Errors in accounting for later renumbering may account for this. The locomotive now at the B&O museum may be the former #3 Thomas Jefferson. Can anyone clear this up?

Nope, she's not Thomas Jefferson. No. 8 was an improved version of the earlier grasshoppers, being built with a cab and both axles were powered. Up until 1892 it was used to switch the Mt. Claire shops before it was retired and temporarily renamed. Atlantic better resembles the earlier design, although it was of the same design as No. 8 when built It was modified by removing the cab and side rods in 1892, but retains the larger boiler and cylinders of the improved grasshopper class of engines.

Thank you Dylan. So the John Hancock was the last of the Grasshoppers rather than the first of the Crabs. Did Gillingham & Winans build geared locomotives for anyone other than the B&O?