THE ROYAL ARTILLERY INSTITUTION. 
119 
Some guns thus constructed have shewn remarkable strength and endur¬ 
ance, and it is to be hoped that all those about to be converted may be 
equally satisfactory. There is no doubt about their circumferential strength 
or non-liability to burst the barrel, but some good authorities on the subject 
consider them longitudinally weak or liable to blow the breech off without 
any warning. 
The cost of a converted gun is about two-thirds that of an E gun of 
similar calibre. In this estimate the old gun is supposed to have been 
useless as a gun, and worth only £3 a ton, and not a serviceable piece 
worth £21 a ton. 
But the expense in gunnery is not so much the first cost of the gun as 
the ammunition it uses and the service it requires; for example, the ammuni¬ 
tion for a 64-pr. costs at least a guinea a round, and if we add the price of 
1000 rounds to that of the gun, we gain only 6 per cent, by adopting the 
Palliser system, whilst the difference between the cost of two live ships of 
war, the one with an armament of converted guns and the other with our 
more trustworthy wrought-iron guns, is appreciably nothing. 
The efficiency, therefore, of a gun should not be sacrificed to economy of 
manufacture, unless under most pressing circumstances. 
However whether Major PallisePs method proves in the end economical 
or not, he deserves notice for the ingenuity, energy, and perseverance he 
has displayed in the matter. 
Mountain guns . 
While the naval service has been calling for the largest guns we can 
make, the lightest ordnance has been required for mountain warfare. 
In fact, there have been four different patterns of rifled M.L. mountain 
guns, all 7-prs., the latest of which is the lightest; viz. two of bronze 
weighing respectively 224 lbs. and 200 lbs., and two of steel, the one for 
Bhootan weighing 190 lbs., and the other for Abyssinia. 
This last pattern, weighing 150 lbs.—only a quarter of the weight of 
the projectile for the 12" gun—has been sealed to guide future manu¬ 
facture. 
The Abyssinian gun was designed in the Boyal Gun Eactories, where 
the two batteries (12 guns) were manufactured within six weeks of the 
date of order, from steel blocks furnished at four days notice by Messrs 
Eirtli & Co., Sheffield* 
The steel blocks were cast similarly to those used for the steel barrels 
of Woolwich guns; indeed, the manufacture of the mountain gun is very 
similar to the preparation of a steel tube, the solid block being bored, 
toughened in oil, rifled, and turned down to proper size and shape. 
The calibre of the gun is 3"; the rifling is a uniform spiral of one 
turn in 20 calibres; the grooves have angular sides like those of the present 
* Memorandum on the 7-pr, mountain equipment for special service in Abyssinia, by Colonel 
Wray, C.B., R.A., 1867. 
