the dogs used in investigation

[Pcdunn]

They both look to be females, in the sketch above-- surely at least one was a male dog, to judge from the name "Barnaby"? Maybe it's just Victorian sensibilities again? Or perhaps those aren't the bloodhounds of interest?

[Shaggyrand]

Burnaby and Burgho, the bloodhounds Edwin Brough owned used in the trials in Hyde Park, October 1888, that Sir Charles Warren attended.

Wrong dogs. Those are Rosemary and Duchess of Ripple (Burgho’s dam). The illustration is from American Book of the Dog, 1891.

[Pcdunn]

^^^ Aha! Attention to details wins again. Thank you for the clarification, Shaggy.