THE DRIFT OF SERVICE PROJECTILES. 
473 
ratus’that is on the table there to your right that he tried to show off last year, 
but found out of order ; it had not been used since he left The Academy 25 years 
before. I have been putting it in order and trying to make it work, but I only 
succeeded in so doing this morning and, consequently, have not fired more than a 
few rounds from it, so the results that I obtained are valueless, except, perhaps, 
on one point. The lecturer suggested that he had heard that projectiles when 
they lose their velocity have a tendency to lose their drift to the right and Captain 
Lloyd showed the same thing, I understand. That, perhaps, is the only point 
which I found most distinctly shown by the few rounds that I was able to fire to¬ 
day—namely, that if the projectile loses its velocity when fired at a high elevation 
it not only loses its drift to the right, but drifts most distinctly to the left. I 
actually obtained a large amount of drift to the left. 
Colonel R. W. Rainsford-Hannay —I do not understand the high mathe¬ 
matics involved in the question of.drift. My experience with high trajectories and 
low velocities inclines me to think that up to a certain elevation there is an increasing- 
drift to the right and, as the extreme elevation of the howitzer is approached, the 
drift to the right gets less and less, and that when the maximum elevation is 
reached at which you have control over the projectile it gives a swoop to the left 
and falls a considerable distance to the left of the line of fire. This elevation is, 
as far as I can recollect, between 57° and 62° with 6" B.L. and 65° and 70° with 
8" B.L. howitzers. You may, up to that point, have had fair control over the 
projectile, but as soon as you reach it the projectile becomes wildly erratic, though 
its general tendency is to go to the left. At least that was our experience at 
Lydd, and I think Captain Osborn, who was experimental officer there three 
years ago, can bear out what I have said. 
Captain G. Osborn— -With regard to that, Sir, I can only say that the experi¬ 
ment lias been tried at Shoeburyness as well as at Lydd, after it first had been 
remarked at Lydd that that was the case; as regards the figures they are some¬ 
what astonishing and, as I believe they have not yet been before the Institution, 
I may be permitted to mention them. Those to which I refer are from the 
8" howitzer, not the 6". The 6" howitzer, it is true, gave suddenly (after 65° 
elevation was reached) deflections to the left of about 260 yards, so far as I re¬ 
member ; that is only from memory, it might be feet, but I think it was yards ; 
but, as regards the 8" howitzer, I have the figures 1 fairly in my mind and they 
1 1 have looked up some of the extraordinary rounds referred to by Colonel Rainsford-Kannay; 
they were as follows :— 
Weather calm on the day on which the first three rounds were fireJ, and a light breeze only 
when the remainder were fired. 
Elevation 
Deflection 
Shell fell left 
Charge 
Remarks 
Feet 
Cordite 
67° 
5° 
255 
+ 2 6 oz, rings 
68° 
2° 30' 
240 
*69° 
2° 30' 
1320 
,, 
Blind 
59° 10' 
60 { 
All were appr’xim’tely 
\ f 
Seven consecutive 
line and range 
) ” l 
rounds were fired 
69° 
6° 
399 
69° 
6° 
387 
„ 
69° 
6° 
540 
l + 1 6 oz. ring ^ 
Range of this round 
about 1400 yards 
♦This round was dug up and found only three feet below the surface of the shingle and point uppermost. 
It is evident that the long shell, fired at high angles of elevation, with small charges is very 
erratic. It would be interesting to know what limits there are to the drift of the 4£ calibre 8" B.L. 
shell when fired at very high angles with various charges; and very necessary to know the angle 
of elevation up to which each charge gives satisfactory shooting. 
