MINUTES OE PROCEEDINGS OE 
222 
As the charges and weights were identical, this large difference must be 
mainly attributable to the imperfection of the instrumental arrangement, 
and makes a reduction to the muzzle—which at the most would amount to 
an additional foot or two—of no importance. It is probable that the 
longest interval, giving the slowest rate of translation, or least value of V, 
is nearest the truth. There is so much that is historically interesting in 
this part of the story that I shall be excused for going a little more fully 
into it. 
27. The subject was brought before this Institution so early as July 17, 
1841, when Professor Wheatstone, on the introduction of the late Captain 
Chapman, E.A., E.E.S., delivered a lecture, Lieut.-General Lord Bloomfield 
being in the chair, upon the properties of his electro-magnetic chrono- 
scope, “and the likelihood of its application to the practical purposes 
of artillery—viz., to ascertain the time of flight at different ranges, as also 
the initial velocities of shot.” There were twenty-two officers present, and 
I extract an account of the instrument from the unpublished minutes of that 
year, which is anterior to the first volume of published “ Proceedings.”* The 
invention of the instrument only dates from the beginning of 1840, and this 
was very nearly its first publication. The only earlier account will be found 
in the Bulletin of the Academy of Sciences, Brussels, for October 7, 1840.f 
Not long after—in April, 1843—one of the chronoscopes was presented to 
the physical cabinet of the Eoyal Military Academy. It cannot now be found. 
That the enquiry made no progress at Woolwich, at that time, was no 
fault of the Professor's; the causes would not be difficult to unravel, but no 
useful purpose w r ould result from the attempt. The first actual application 
of one of these instruments to a ballistic purpose seems to have been in 
Sir James South's grounds at Camden Hill, October 6,1842, when a number 
of determinations were made of the velocity of a bullet fired with a single 
and a triple charge, from a pistol furnished by Purday, of Oxford Street, 
which gave respectively 630 ft. and 1177 ft. per second. Unfortunately, the 
memorandum before me does not state the weight of the charges or bullet; 
the velocities deduced are, however, not far from the ratio of */3 to 1 if we 
take the higher velocity as standard. 
28. The instrument employed in 1857 was not identical with that of 
1842, being a great improvement on it, but it resulted from the development 
of the same idea. It was tested previously, by observing the time of falling 
of a body in air through spaces of 1*5 ft. and 6*0 ft. respectively. These 
times, by the well-known formula, are 0’30527 second and O’61054 second. 
The instrument gave on different days the following measurements 
6 ft. 
September, 1857, before Sir J. Burgoyne and Sir W. 7 n ^~ 
Reid, R.E. j bU> dir ‘ 
October 15, 1857, before the Ordnance Select Com- 7 o 11 a 
mittee. Eardley-Wilmot observer .) 0 " 
October 24, 1857, before Mr. Mallet . 607| n 
November 3,1857, before Prof. H. Lloyd and Major- 7 an> 7 ' 
General Cator .’. \ " 
1-5 ft. 
300| div. 
SOdJ n 
303f „ 
311* » 
* See Appendix to this paper. 
f See “ Handbuch der Angewandten Electricitatslelire,” by Rarl Kuhn, Lcipsig, Voss, 1866, 
for a chronological abstract of the successive applications of current electricity. 
