402 



TRANSACTIONS OF THE AMERICAN INSTITUTE. 



I have stated that g-uns are more likely to burst when fired on cold or rainy 

 days, and oifer the following examples in corroboration: first, two large 

 steel guns, of my fabrication, burst under such circumstances, then this 

 example of the gun on the Naugatuck, and two guns referred to in the 

 appended table, are among many other similar cases I have noticed. 



r Meteorological Observations, and number of rounds fired each day. A table 

 y. from Rodman'' s book, showing that guns burst on cold and rainy days. 



Diagrams of fractures of guns No. 335 and 983 ca7i be seen on pages 69 



and 70, Rodman's book. 





Oct. 



Nov. 



22 ... , 



27.... 



28 ... , 



29..., 



30..., 



31..., 



2..., 



3.... 



4..., 



5..., 



7.... 



11.... 



12..., 



13.... 



U..., 



16.... 



17.... 



18.... 



19.... 



25.... 



42.33° 



43.33 



42.33 



43 



42 



43.33 



48. G6 



42.66 



42.66 



52.66 



66 



37 



43 



42.33 



34.. "53 



39.66 



40.33 



42.33 



83 



17.66 



WEATHER. 



Cloudy; fog at 7 a. m 



Cloudy ; atmosphere hazy . . 

 Cloudy; atmosphere hazy .. 

 Cloudy; atmo.sphere hazy .. 

 Cloudy; atmosphere hazy .. 



Fair 



Pair 



Fair; atmosphere hazy 



Showery 



Showery 



Fair 



Cloudy ; shower at 4 p. m. . . 



Cleared up at 11 A. m 



Occasional sprinkle of snow. 

 Occasional sprinkle of snow . 



Rain and sleet 



Cold rain 



Occasional sprinkling of rain 



Rain and snow 



Fair 



NO. OF CHARGES FIRED 

 EACH DAY. 



3.'?4. 



Proof 2d. 

 12 

 14 

 20 

 20 

 20 

 20 

 25 

 25 

 32 

 20 

 31 

 31 

 32 

 32 

 32 

 33 

 56 

 8 

 64 



335. 



Proof 2d. 

 12 

 14 

 20 

 20 

 20 

 20 

 25 

 25 

 32 

 20 

 31 

 31 

 32 

 32 

 32 

 31 



Gun 



Burst. 



983. 



Proof 2d. 

 12 

 14 

 20 

 20 

 20 

 20 

 26 

 25 

 11 



There being two forces acting upon guns which burst one the direct 

 pressure of the gases evolved from the powder, and the other resulting 

 from the expansion by heat of the inner metal of the gun, both forces acting 

 in the same direction, and nearly at the same time, it would seem difficult 

 to show one to be pre-eminently the cause of the fracture. 



The fractures of large guns upon improved models, with a light chase 

 and heavy re-enforce, that have burst with the service charges, are curiously 

 alike in their direction, running through the center of the breech aud 

 re-enforce, to a point usually forward of the trunnions, and branching off at 

 either side, generally breaking the M/y.ff. 



gun into three pieces. This direc- ,— 



tion of fracture holds whether the 



gun has the outlines of the army 



columbiad, of the Dahlgren gun, or 



of the Parrott gun with its strong wrought iron re-enforce, and whether the 



gun be made of steel or of cast 

 iron. It would scarcely be ex- 



pected, when the Dahlgren gilns 

 burst, with this great thickness of 



