Sherlock Holmes has the reputation of being relentlessly dour — in “The Adventure of the Mazarin Stone” Watson even says that “Homes seldom laughed.” To counter this, A.G. Cooper counted up 292 instances of Holmes’ laughter, and Charles E. Lauterbach and Edward S. Lauterbach even compiled this table:

Frequency Table Showing the Number and Kind of Responses Sherlock Holmes Made to Humorous Situations and Comments in His 60 Recorded Adventures

Smile: 103
Laugh: 65
Joke: 58
Chuckle: 31
Humor: 10
Amusement: 9
Cheer: 7
Delight: 7
Twinkle: 7
Miscellaneous: 19
Total: 316

The explanation, they suggest, is that Watson was deaf.

(A.G. Cooper, “Holmesian Humour,” Sherlock Holmes Journal 6:4 [Spring 1964), 109-113; Charles E. Lauterbach and Edward S. Lauterbach, “The Man Who Seldom Laughed,” Baker Street Journal Christmas Annual No. 5 [1960], 265-271.)