Long before there were computers and fonts, publishers used fancy letter images like this one of the letter S as drop caps. You too can use this drop cap S image because it is in the public domain.
The publishers of Stories of Whitminster did not identify an illustrator but this image may have been a stock sort of image used by a number of publishers to decroated their works in 1873.
This image is copyright free and in the public domain anywhere that extends copyrights 70 years after death or at least 120 years after publication when the original illustrator is unknown.