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MINUTES OF PROCEEDINGS OF 
retarding force in the shape of minus pressure or suction, from the 
partial vacuum formed behind the base of any projectile moving rapidly. 
To this suction must be attributed a fact brought out by these investi¬ 
gations—viz. that the actual retarding pressure on a spherical 9-inch shot 
AMBN in fig. moving at a velocity of 1130ft. per second is 555 lbs., while 
that on an elongated 9-inch shot with a hemispherical head AMBBC 
moving at the same velocity is only48 7 lbs. But the anterior portions AMB 
being identical, the decrease of pressure of 68 lbs. on the elongated shot 
must be due to the air closing in more easily behind it. I now speak 
of the question of actual resistance , which must not be confounded with 
the greater power of overcoming resistance possessed by the elongated 
shot as compared with the spherical, which may generally be about 
3 to 1. 
Further, the service ogival-heacled 9-inch shot AM'BBC meets with 
98 lbs. less pressure on it than a hemispherical-headed one. So that the 
advantages in keeping up velocity possessed by the service form of 
shot as compared with a spherical one are more than would at first 
appear; for while the pressure of air against the latter is 555 lbs., it is 
only 389 against the former, and to meet that pressure there is three 
times the weight and momentum. 
General Maievshy on the Blight of Projectiles. 
The investigations of General Maievsky, as to the forces acting on 
projectiles in flight and penetration, are such that they form a study of 
great magnitude, involving peculiar applications of the highest mathe¬ 
matics. It would be idle to attempt to take up the pursuit of this 
subject without making it a regular course of study. A few of 
Maievsky^s results quoted by Mr. Mallet in his papers in the “ Engineer,” 
as well as notes on the subject of penetration, as discussed by Mr. Mallet, 
may be found valuable although briefly given in general terms. 
1st. As to the irregular spiral path described by rifled projectiles in 
flight:— 
General Maievsky supposes the projectile to be proceeding on a path 
not absolutely coincident with its axis, and shows that the point where 
the resultant of the resistance on the anterior part of the projectile 
