The Clammer and the Submarine, by William John Hopkins
Houghton Mifflin, 1917
This curious cover is identical to the cover of Hopkins' The Clammer (1906) with the addition of a submarine's periscope and the ship's wake! Sacker may not have been involved with this modification, as she had largely stopped doing cover design by this time. The monogram is very sloppy, too. In 1925, Houghton Mifflin published the title below, with only the "remnants" of Sacker's design!