I agree about your frustration Simon. I have searched long and hard through archives of newspapers and magazines as well to no avail.
I do have the Vermeire 1922 though and check out how I calculated the teaspoon volume.
“There are between 16 and 18 teaspoonfuls in a cocktail glass (1/2 gill measure)”.
Calculation: ¼ gill = 1 ounce between 8 and 9 tsp and so tsp = 1/8 ounce (old spoon) - 1/9 doesn't make sense.
I do have the Vermeire 1922 though and check out how I calculated the teaspoon volume.
“There are between 16 and 18 teaspoonfuls in a cocktail glass (1/2 gill measure)”.
Calculation: ¼ gill = 1 ounce between 8 and 9 tsp and so tsp = 1/8 ounce (old spoon) - 1/9 doesn't make sense.