TRACT 34.

IN GUNNERY, 1785.

for the correction of g and n } they become

= 78-33 + — —b,

' +, -L. 7. 7

N = 40-07 -

p + b140-07 bi{i- 87-16)

10855700 + }t(i + 87-16)’or n = 40-07 - nearly.

And by these theorems the numbers in the columns g and nare made out, the mean value of i, or point struck, being90-1.

The last 6 rounds were fired down the river from theConvicts’ or Proof Wharf at A, and the place of the fallobserved by two parties of the cadets, stationed at d and e.The gun had 15 degrees elevation. The fall of the firstonly could be seen at the gun, where the time of flight wasobserved by a stop watch, and found to be 14 seconds. Thetwo parties of observers at d and e had no time-piece withthem, so that the other times of flight could not be ob-served. The medium range is 5916 feet or 1972 yards.The last two balls went close over the heads, and just fellbeyond, the lower party of observers, at e ; yet notwith-standing their imminent danger, they gallantly resolvedto keep their ground, if any more rounds should be fired,not knowing immediately that we intended not firing any-more at that time. These two rounds were probably de-flected thus a little from their course by the usual causes ofdeviation. And perhaps the tw-o former rounds had beenstill farther deflected, and thrown on the land, as theobservers saw nothing of them. But the gun was pointedip a direction rather nearer this south side of the river.