410 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



in cooling." Now I have never claimed that heating a gun would burst it, 

 or that cooling it would burst it; but that heating or cooling one part of a 

 gun to a certain degree, while the remaining part was at a diii'erent state 

 of temperature, would burst it, and that the degree of this unequal expan- 

 sion necessary to burst a gun, must be greater than the elasticity and 

 ductility of its metal. I have also included in my argument the compressi- 

 bilit}' of the metal; but as compressibility goes before elasticity, and as a 

 gun would be destroyed as effectually if its compressibility were great, 

 by permanent enlargement of the bore, as if it were burst, it is not neces- 

 sary to include it in a general statement. 



HOW TO MAKE GREAT GUNS. 



For armored ships, and for revolving forts, guns require to be constructed 

 in a different manner from those heretofore used, or those intended for 

 other purposes. But whenever a gun is produced that will penetrate iron 

 plates, of the greatest practical thickness that can be carried on a ship's 

 hull, the day of iron-clads will have gone by, and fast sailing and manoeu- 

 vering steamships, armed with guns capable of projecting shot with 

 extremely high velocities, will take their place. Howitzers will always be 

 required for earth-works and fortifications, which makes it desirable tliat a 

 cheap gun of that class should be provided; one that can be produced with 

 dispatch, and is capable of endurance, even if of large size. Of the great 

 number of practical inventions in ordnance which I have prepared to meet 

 required conditions, L shall herein confine myself to describing three 

 general plans of guns which I have devised, viz: a spherical compensaling gun, 

 adapted to a turret, so constructed as to be absolutely safe from bursting 

 when fired with full charges of quick-burning powder, mounted so as to be 

 capable of being worked by steam or by manual laboi-, and so protected as 

 to be entirely safe against penetration by any projectile or part of projec- 

 tile, the turret having no open port. Second, a gun so constructed as to 

 be absolutely safe from bursting, no matter what charge is fired in it, it 

 having strength to resist the full pressure and temperature of the gases of 

 powder, if confined within its bore, even although the pressure were as great 

 as some of the absurd estimates heretofore noticed; arranged so that much 

 higher velocities can be given to the shot than have heretofore been deemed 

 possible, and which it is practicable to make of any required size and still 

 retain these qualities; and the third a cast iron gun or hoivitzer that can be 

 produced for less cost than the ordinary large cast iron guns, and which I 

 believe is practicable for a caliber of twenty inches. 



I should have felt some hesitation, perhaps, in proposing an entire new 

 system of ordnance, for which a variety of guns, turrets, carriages and 

 implements had to be devised, merely as an innovation, but being convinced 

 that radical changes and improvements were imperatively demanded by the 

 requirements of the service, I have so adapted my improvements as to 

 meet all the required conditions. I feel more confidence in my position 

 from the fact that my readers will perceive that conclusions, exactly the 

 opposite to those drawn by the theorists who have heretofore written on 

 the subject, are unavoidable, even from their own examples. I hope my 

 conclusions will not be considered less trustworthy, because I have dis- 



