During his summer seasons in Rockport, Hornby noted that many pupils chose the venerable, dilapidated shed on the edge of the inner harbor. Its prominence and its simple but interesting proportions made it a natural model for sketches and paintings, good and bad. One day when a student brought for criticism a pencil drawing of the house, Hornby exclaimed, “What-Motif No 1 again!” It has been that ever since."
—Rockport Sketch Book, by John L. Cooley
History of Motif No. 1