342 Mr. Mallet on the Physical Conditions 



technia," Venice, 1550; and Collado, " Practica Manuale del Artiglieria," Milan, 1G41. 

 The French found, on taking Algiers in 1830, numbers of shells weighing nearly 900 lbs. ; 

 and the Swedes, in 1642, used shells of 462 lbs. weight, and holding 40 lbs. of powder; 

 and, in most arsenals of Europe, an old shell or two, from 16 inches to 18 inches diameter, 

 may be found preserved as a curiosity. 



With the exception, however, of the attempt made by the French, in 1832, to construct 

 a 24-inch mortar, and apply it at the siege of the citadel of Antwerp, no essay seems to 

 liave been made in recent days to realize the vast increase of power that such large shells 

 must confer; scared, apparently, by their former abandonment, which (Antoni, " Uso 

 delle Armi da Fuoco," Torino, 1780, states) arose from the awkwardness of loading, which 

 prevented more than one discharge in forty minutes, and from the great cost of the manu- 

 facture of such shells in the condition of iron-founding at that time. A 20-inch mortar 

 was cast in England, some years since, for the Pacha of Egypt, a solid shot from which, 

 on proof at Woolwich, penetrated the butt to an enormous depth ; but it never appears 

 to have been used. 



The " Monster Mortar" of Antwerp, as it was called, was designed by Colonel Paixhans, 

 and cast, at Liege, by direction of Baron Evain, Minister of War. Its form was crude ; a 

 mere cylinder, embedded in a mass of timber. The dimensions of the mortar were : — 



Inches. 



Total length, 59 



Diameter outside, 39-5 



Caliber, 24-5 



Length of chase from top of chamber, . 27 



Depth of chamber 19 



Diameter of chamber, 9 



When afterwards burst at Brasohaet, the casting was found to present those defects 

 which, upon principles developed in the text, are inevitable to huge masses of cast-iron, 

 suddenly varying in solid dimensions. 



The weight of this mortar was 14,700 lbs. ; that of its bed, 16,000 lbs. ; the weight of 

 the empty shell was 916 lbs. ; the charge, 99 lbs. of powder ; giving a weight for the shell 

 in flight of 1015 lbs. The chamber of the mortar would hold 30 lbs., but about 12 lbs. of 

 powder were found sufficient to throw the shell 800 or 900 yards. When brought into 

 position against the Citadel, at about 1000 yards range, after one or two preliminary 

 trials, it was found that a shell could be fired about every forty minutes, the loading being 

 performed by an awkwardly constructed balanced lever or " chevalet." But few shells, 

 however, were fired,— not above twenty in all, — all those provided, which had only an 

 average thickness of about 2 inches, being fovmd so weak about the " culot," or bottom of 



