Small correction: The illustrator here is actually "H.", not "M.", Petherick. Specifically, Horace Petherick, who also illustrated etext #24105 and some other Gutenberg titles. Enlarging the image with the signature makes the initial more clearly an H (it may appear as an M if you don't zoom in). John David Widger wrote:

A Forgotten Hero, by Emily Sarah Holt 23119 [Subtitle: Not for Him] [Illustrator: M. Petherick] [Link: http://www.gutenberg.org/2/3/1/1/23119 ] [Files: 23119.txt; 23119-h.htm]