Ferris looked to many sources for historical details. Next to the ship sketched in ink on the recto of this unsigned sheet is the name of Johannes Stradanus, a Flemish painter and draftsman. His work, <i>Tracing the Magnetic Pole</i>, shows a ship much like this one, hanging from the ceiling above the desk of a scholar.
Two women are sketched in graphite on the verso; Jean-Michel Moreau le jeune (1741-1814) is credited as the source for one of them in the note "headdress Moreau le jeune 1776-80". The younger Moreau published a costume book "Monument de costume physique et morale" which is a record of dress and manners of the French nobility. It is not known what picture Ferris was researching, although sometime around 1920 he did paint John Paul Jones at the French court in 1780.
