ARTILLERY 239 



' In trying these various bullets, a number of each kind was fired against a^vertical 

 1 >ank at a distance of 435 yards. Tho gun was constantly pointed at the same object ,and 

 the closeness of the bullet-holes to each other was taken as the criterion of accuracy, 

 while the drop below the level of the aim furnished an indication of comparative range. 



' The conclusions arrived at from these and other experiments may be concisely 

 stated as follows : 



' 1st. A pointed form at the front end of the bullet is unfavourable to accuracy of 

 flight, unless the cylindrical part of the bullet be of considerable length ; but, on the 

 other hand, a pointed or conoidal form behind, has the effect of increasing the accu- 

 racy attained. This may be explained upon the very probable supposition that the 

 blast from the mouth of the gun, impinging upon the rear of the bullet, will operate 

 more unfavourably upon a flat or hollow end than upon a rounded or conical one. 



' 2nd. Increase of length in the cylindrical part of a bullet always increases 

 precision ; but, when carried beyond a certain limit, lessens the initial velocity, even 

 where the charge is proportionately augmented. 



' 3rd. Both range and accuracy were affected in an important degree by the manner 

 in which the bullet fitted the contraction in the gun. When the fitting part was in 

 front of the bullet, the pressure of the gas operating upon its sides compressed it, and 

 the same effect was produced, though in a less degree, when the conical, or rounded 

 end at the back, projected too far into the powder-chamber. 



'These effects were rendered apparent by inspection of bullets recovered after firing, 

 many of which were found in nearly the precise condition in which they quitted the gun. 



' The bullet ultimately selected is a little longer and heavier than those experimented 

 with, and differs from the pointed bullet, in being longer in the cylindrical part and 

 having a coned, instead of a rounded, end behind ; and although its drop in a range 

 of 435 yards is considerably more than that of several of the shorter bullets, yet there 

 is little doxibt it will excel them in range at higher elevations of the gun ; because I 

 have found that a pointed front only operates in sustaining the flight of the bullet 

 when the range is long ; and a high initial velocity, which materially lessens the 

 drop in short distances, does not produce the same effect, in a corresponding degree, 

 when the distance is increased. 



' Great improvements were effected in the accuracy of the firing, by modifying the 

 shape of the projectile ; but although the experiments were very protracted, I feel 

 that they require to be further prolonged in order to arrive at the greatest attainable 

 perfection in the form of the bullet. 



The ranges at different elevations were not ascertained with the form of bullet 

 iiltimately adopted ; but with a three-pound pointed bullet and charges of twelve 

 ounces of powder, they were as follows : 



Ranges with the rijled gun and three-pound bullets. 

 Elevation. Range in Yards. 



4081 



1 

 2 

 3 

 4 

 5 

 6 

 7 



770 



1,112 I Measured to first graze 

 1,500 [upon a plane about five 

 1,840 [feet below the centre of 

 2,056 the gun. 

 2,300 

 2.600J 



' The powder used was a mixture of blasting and ' double-seal ' powder in equal 

 proportions. The distances given are in most cases averages of several shots ; but 

 in some instances they were only approximately determined. When the gun had 

 more elevation than 7 the bullets could only be fired out to sea, and the range could 

 not be ascertained. 



' By way of comparison with these results, an extract is here given from the last 

 edition of Sir H. Douglas's ' Naval Gunnery,' specifying the ranges obtained with a 

 68-pounder throwing shot with full charges, which ranges, it will be seen, are, upon 

 the whole, no greater than those of the three-pound bullet fired from the rifled gun : 



Ranges with a 68-pounder. 

 Elevation. Range in Yards. 



340 



1 833 



2 1,247 



3 1,558 



4 1,737 



5 2,036 



6 2,337 



7 .,,......, 2,440 



