Tests of the pumps and wells of the University of Illinois
An undergraduate engineering thesis by Norval Enger, submitted at the University of Illinois in 1906, reporting field tests of the campus air-lift pumps and wells. Plates are hand-drawn in ink on printed yellow graph paper: performance curves plotted with circle and triangle markers, hand-lettered axis labels, and a sectional diagram of a perforated air-pipe head with dimension callouts.
