One enterprising Golden Age English mystery writer, Jefferson Farjeon (1883-1955), had the originality to make just such a "passing tramp"--a cheeky Cockney fellow named Ben--into one of the era's unlikeliest series detectives. Ben appeared as the lead character in a series of eight Jefferson Farjeon crime novels, published between 1926 and 1952. Ben also featured in an early Alfred Hitchcock talkie film, Number 17 (1932), which was based on the hugely popular play by Farjeon of the same title (it was also novelized by Farjeon).
Pictured at the top of this post (and, indeed, at the top of the page) is Leon M. Lion, a popular English actor who played Ben on screen (and on stage). I much prefer the Ben of Farjeon's books, because over the course of the series Ben develops greater depth than Leon M. Lion's film version, who rather reminds me of Moe of the Three Stooges. Be that as it may, the dust jacket of Detective Ben (1936), seen below, clearly owes a debt to Mr. Lion.
One of the Ben novels was reprinted in 1986 by the Collins Crime Club as part of H. R. F Keating's "Disappearing Detectives" series. Ben is worth reviving, both for his own intrinsic merit as a character and as evidence that the Golden Age mystery did not always revile the lower classes. Author Seton Dearden approvingly wrote of Ben that he "is a mixture of Trimalchio and the Old Kent Road, a notable coward, a notable hero, above all a supreme humorist"; while the Saturday Review lauded his "adorable Cockney insouciance and nerve."
Interestingly, Jefferson Farjeon was a brother of Eleanor Farjeon, the famous children's writer, and a son of Benjamin Farjeon, a Victorian-era novelist who during a highly prolific writing career produced several worthwhile mystery sensation novels. The son carried with him something of the father's interest in and empathy for England's poor and downtrodden.
Jefferson Farjeon's "Ben" Mystery Thrillers
No. 17 (1926) (filmed by Alfred Hitchcock as Number 17 in 1932)
The House Opposite (1931)
The Murderer's Trail (1931)
Ben Sees It Through (1932)
Little God Ben (1935)
Detective Ben (1936)
Ben on the Job (1952) (reprinted 1986)
Number 19 (1952)