I found these two words in “The Hound of the Baskervilles” in The Greatest Adventures of Sherlock Holmes. To find the meaning of the words this time, I turned to a Sherlock Holmes website. From the context, I could guess that wagonette was some kind of horse drawn wagon and cobs were the horses. And that is exactly what it meant.

Wagonette and Cobs – A wagonette, as its name implies, was an open wagon with side benches, rather more rustic than any conveyance Watson would have been used to in London. Cobs are sturdy draft horses, used for farm work. (definition found on Discovering Sir Arthur Conan Doyle from Stanford University)

Usage: “The train pulled up at a small wayside station and we all descended. Outside, beyond the low, white fence, a wagonette with a pair of cobs was waiting.”

photo credit Horse & Hound