involved in the Construction of Artillery. 365 



but been better than that of, the French howitzer, or mortar, taken at Cadiz, and now in 

 St. James's Park, — an instrument well designed, by obviously competent men, and which, 

 though made under difficulties, and of inferior material, answered its intended object. 



It would have been of much interest and value, to have been able to corroborate the 

 truth of the views I have here advanced, as to the causes of the failure of these Baltic 

 mortars, by a few experiments on their metal. With this view I applied for a portion of 

 each split one (a pair of bars, together not more than 5 lbs. or 6 lbs. weight), and stated 

 my views and object; but was refused by the Oidnanoe Select Committee, at Woolwich, 

 on the ground that they wanted the mortars (Ji/teeii toils weight of metal !) lor their own 

 experiments. A second application, receiveAfor answer, that after the Committee should 

 have reported on its own experiments, it would consider my application ! 



Months have since elapsed, but I have never heard further as to my application ; I 

 have learned, however, that experiments, similar to those which I indicated, and requested 

 the means of making, have been since performed. 



In concluding this Note I may mention, that an officer stationed in the Baltic informed 

 me, that these mortars were tired for some time, as fast as they could be loaded, — perhaps 

 at the rate of twelve shells per hour, or more. Possibly the success of the bombardment 

 demanded great rapidity of fire : but the French mortar-boats, having two mortars on 

 board, which can be fired alternately, possess an advantage over ours with but one. 



A heated mortar will be most safely and readily cooled by filling it up to the brim 

 with cold water, as rapidly poured in as possible. The water may be easily taken out 

 with a gutta-percha syphon, and the interior dried with a swab. 



The method and mixture of cast-iron, described in sect. 59, is that still actually in use 

 in foundries employed casting ordnance by contract for Government, and is just the mate- 

 rial of which the Baltic mortars consisted; the grain of the metal of those split was as 

 coarse as granite. 



One of these was cast at Carron, perhaps more than forty years ago ; so the malpractice 

 is an old one, and its evil results have nothing to do with " hot-blast." 



Imagined Causes of Inferiority and Superiority in various Cast-Irons. 



It is stated in the "Report of the Commission of Inquiry," p. 17, as to the manufac- 

 ture of ordnance on the Continent, which has appeared while those sheets have been 

 passing through the press, on the authority of Schiir and Mitscherlich, that in Swedish iron 

 works, pyrites (sulphurct of iron) is thrown into the furnace, with the other constituents of 

 the charge, to produce the fine, gray, mottled iron required for gun-founding ; and it is 

 added, that the eflect may be analogous to that of the oxidizing flame in a reverberatory 

 furnace, — some doubt being at the same time expressed as to the accuracy of the reported 



VOL. XXIII. 3 B 



