According to Jess Nevins's web version of his Encyclopedia of Fantastic Victoriana, 'Blue Cap was first published in The Boys' Standard in 1875 or 1876 and was reprinted as a pamphlet in (perhaps) 1878 and then in The Boys' Leisure Hour in 1885.'
Nevins states that 'Blue Cap the Bushranger is not one of the better-told penny dreadfuls, although Borlase's knowledge of the Australian environment is displayed in some nicely concise descriptions. But overall the story has the flaws of the penny dreadful style: continual movement and action, stiff and lifeless prose, forward momentum with only the slightest pauses for scene-setting or characterisation, and the ubiquitous one-line paragraph [...] The over-riding characteristic of Blue Cap, however, is its bloodthirstyness. Blue Cap is one penny dreadful that deserves the title "penny blood." Borlase has a body count of at least two dozen, with Blue Cap himself being responsible for at least half those deaths, including the execution of women and children. There are also attacks by the aborigines (about whom Borlase uses the N-word with abandon), an inn where travelers are murdered and thrown into a cellar full of red ants (which then pick the bones clean), and corpses discovered wrapped in death grips with the snakes which killed them. Blue Cap is a violent, brutal penny blood, which I'm sure thrilled and titillated its audience.'