Tests of several types of small gasolene engines
A 1906 mechanical engineering thesis by Warren Kenyon Henning and Horace Healy Morgan at the University of Illinois, reporting bench tests of small gasolene engines for faculty examiners. The plates are hand-inked line graphs on printed graph paper, with plotted circles, crossing curves, and stacked left-hand scales labelled in draughtsman's block capitals "Cost," "Gasoline," "Eff." — usable as vintage chart texture and hand-lettered annotation.
