chronograph

noun

1. (obsolete)A chronogram.
2. A device which marks or records time or time intervals.
3. A combination of a watch and a stopwatch.

   “Along this critical length Sir Nigel [Gresley], completely unmoved and in a very cheerful humour, came into my compartment and sat down next to me, with the immense chronograph in his hand that he had had made specially for speed recording; [...].”

verb

1. To make an accurate measurement of the speed of a projectile.