Experiments with Cannon, &c. 183 



found them to be very useful guns, especially when they 

 were fired with a grape composed of 6 or of 9 pound 

 balls; but at Munich these experiments were made on a 

 much more extensive scale. 



It had been asserted by those who did nof approve 

 of the introduction of iron ordnance for the land ser- 

 vice, that, although iron guns of a very large calibre, 

 such as are used on shipboard, are found to be suffi- 

 ciently strong, yet smaller guns, such as would be 

 proper for field artillery, would be very liable to burst, 

 if they were not made much heavier than brass guns of 

 the same bore ; which would render them unwieldy, and 

 unfit for those rapid movements which are often so de- 

 cisive on a day of action. 



Were this objection founded, it would undoubtedly 

 be decisive against the general introduction of iron 

 guns ; but from all the inquiries I could make I 

 thought there was reason to conclude that want of 

 strength^ which was certainly very apparent in iron guns 

 of inferior dimensions, arose from accidental circum- 

 stances ; and that an effectual remedy might easily be 

 found for that imperfection. 



Until iron guns were cast so/id, or without a core, no 

 hopes could reasonably be entertained of being able to 

 cast small guns of that metal so sound, and to render 



o * 



their texture so uniform throughout, as to enable them to 

 resist the force of their customary charges, without rein- 

 forcing them with an unusual quantity of metal ; and 

 even after iron guns of all calibres were cast solid, yet, 

 as the strength, or toughness, of cast-iron depends much 

 on the slowness with which it cools in the mould ; and as 

 small masses cool more rapidly than larger ones, it is 

 evident that guns of a small size would be much more 



