Can’t find that, but in his 1942 book Phil Sharpe had a chapter on chronographs. The most notable being the Le Boulenge’ drop rod and the Chronoscope used by Remington in 1940. But I have found some interesting reading dating to early 1840’s chronograph.
https://en.m.wikisource.org/wiki/1911_Encyclopædia_Britannica/Chronograph
In the Le Boulengé chronograph (“Chronograph le Boulengé,” par M. Bréger, Commission de Gâvre, Sept. 1880) two screens are used. The wire of the first forms part of the circuit of an electromagnet which, so long as it is energized, supports Le Boulengé.a vertical rod called the “chronometer.” Hence when the circuit is broken by the passage of a shot through the screen this rod drops. The wire of the second screen conveys a current through another electromagnet which supports a much shorter rod. This “registrar,” as it is called, when released by the shot severing the wire of the second screen, falls on a disk which sets free a spring, and causes a horizontal knife to fly forward and nick a zinc tube with which the chronometer rod is sheathed. Hence the long rod will be falling for a certain time, while the shot is travelling between the two screens, before the short rod is released; and the longer the shot takes to travel this distance, the farther the long rod falls, and the higher up on it will be the nick made by the knife. A simple calculation connects the distance through which the rod falls with the time occupied by the shot in travelling over the distance between the screens, and thus its velocity ascertained. The nick made by the knife, if released while the chronometer rod is still suspended, is the zero point. If both rods are released simultaneously, as is done by breaking both circuits at once by means of a “disjunctor,” a certain time is consumed by the short rod in reaching the disk, setting free the spring and cutting a nick in the zinc; and during this time the long rod is falling into a recess in the stand deep enough to receive its full length. The instrument is so adjusted that the nick thus made is 4.435 in. above the zero point, corresponding to 0.15 sec. This is the disjunctor reading, and requires to be frequently corrected during experiments. The instrument was modified and improved by Colonel H. C. Holden, F.R.S. For further information respecting formulae relating to it see Text Book of Gunnery (1857)
https://eugeneleeslover.com/USNAVY/CHAPTER-XV-PAGE-1.htmlAberdeen Proving Grounds 1937
1518. Boulengé chronograph. (See Fig. 1502.)-This instrument, invented many years ago by an officer of Belgian Artillery and developed abroad, is still in common use at proving grounds in all countries. It measures the time interval by recording the difference in time of fall of two rods, suspended by electromagnets. The longer (chronometer) rod, being released when the projectile breaks the first screen, is nicked in its fall by a knife released by the shorter (registrar) rod whose electromagnet is in series with the second screen.
Anyways between those 2 it seems they had some various ways to chronograph artillery and bullets back to 1840. Interesting reads.
