The Strange Adventures of Bromley Barnes, published in 1918, includes 12 tales of a retired government official who takes on occasional problems of murder and espionage for his country.
Trent's Last Case was published in 1913. In this full-length novel, artist-newspaperman Trent investigates the mysterious death of a wealthy tycoon.
In the four stories of the "Divinations of Kala Persad" (published in 1895), a young Englishman becomes a detective after partnering with an old man from India with a remarkable insight into human motives.
The short story "Gallagher" (published 1890) introduces us to a young newsboy with grit, loyalty, and determination who tracks down a killer. (Davis only wrote one Gallagher story, but Disney later developed this for television.)