1862.] 25 



I Bounce charge, and at 10 instead of 5, the centre of gravity being 

 above as before. This shot was neither seen to drop in the water nor 

 heard to make much noise. There was about 2000 yards of water 

 then in the creek ; and as the water was smooth, and many practised 

 eyes were looking out, it was thought likely to have passed all the water 

 and fallen on the mud. This view was much confirmed by three 

 similar eccentric disks being similarly fired a few days after, i. e. 

 with 2 ounces of powder and 10 elevation, and centre of gravity 

 above. On this occasion Capt. Jerningham kindly sent out a boat 

 near the 1500-yard range, and men were stationed about the ship to 

 observe. The water was smooth, and, as before, there was about 

 2000 yards of it in the creek. Not one, however, of these three 

 disks was seen to drop by any one, nor were they heard from the 

 boat, so that there could be little doubt that rotation was esta- 

 blished. A fourth eccentric disk was entered, but stuck in the bore, 

 and was pushed down in a position unknown. This was also fired at 

 1 0, and with the same charge as the preceding, and it was seen to drop 

 at about 1000 yards, and was believed to have had no regular rotation. 

 On Oct. 5th, 1859, the gun being on the lower deck, about 1 1 feet 

 above the water, two eccentric disks were fired with centre of gravity 

 above, the gun being laid horizontally, or what is called point-blank ; 

 charge as before, 2 ounces. The first graze of^ both of these shot 

 was between 600 and 700 yards ; and there could be no doubt of the 

 range being due chiefly to velocity, and not to vertical deviation, 

 the graze of the shot succeeding so immediately the discharge 

 from the height of the gun from the water having been about 



I 1 feet, and the gun horizontal. The range, if not due to vertical 

 deviation, must have been due to a velocity of more than 2000 feet per 

 second. In these early experiments with .the model disk-gun, I had 

 not the advantage (as at present) of having previously fired at tim- 

 ber, so as to have learned unmistakeably the effect on the position (as 

 in striking in a vertical or oblique plane) of different amounts of 

 lateral (or undesired) eccentricity ; also I knew nothing of the inju- 

 rious effect of sabots on the shot's rotation when the sabots were too 

 substantial ; consequently the majority of these earlier experiments 

 were most uncertain, and could not be repeated at will. 



I have, however, since, by firing at timber, learned the conditions 

 which secure certain results ; and these I will briefly state. Excepting 

 when the centre of gravity is " above," or within a few degrees of 



