. Annual report of the American Institute, of the City of New York. Science. 406 TRANSACTIONS OF THE AMERICAN INSTITUTE. colder. The outward pressure of the powder at the time of this fracture would surely have carried away so thin a piece of metal; but it remains standing to show that the pressure against the surface had been reduced before the gun broke—a remarkable evidence of the true cause of the bursting of the gun. The diagram exhibiting the place and quantity of heat shows but little heat at any of the surfaces of the gun. From this, also, we may have been hitherto deceived as to the i
. Annual report of the American Institute, of the City of New York. Science. 406 TRANSACTIONS OF THE AMERICAN INSTITUTE. colder. The outward pressure of the powder at the time of this fracture would surely have carried away so thin a piece of metal; but it remains standing to show that the pressure against the surface had been reduced before the gun broke—a remarkable evidence of the true cause of the bursting of the gun. The diagram exhibiting the place and quantity of heat shows but little heat at any of the surfaces of the gun. From this, also, we may have been hitherto deceived as to the importance of the study of its effects; and we can only appreciate it by some experiments like the following: A clean rifled musket, the barrel of which weighed about five and a quarter pounds, was fired twelve times with the ordinary charge, at intervals of five minutes between each discharge. The time during which the surface of the musket was radiating away the heat from beginning to end was, there- fore, about one hour. At the end of this time its temperature was 200*^. The radiation was somewhat hindered by the wood of the stock, which was a non-conductor, partially enveloping the barrel, and the burnished surface of the barrel, which was a non-radiator. The whole amount of powder was less than one ounce, and it communicated this great amount of heat to five and a half pounds of metal. There would be a material difference in the amount of heat communicated in this experiment, if the barrel were not clean inside, as the residuum of powder would be a non-conductor, and would prevent its communication to the metal of the barrel. The tempera- ture of the gases in a large gun, say 100-pounder rifled cannon, would be much greater than in a musket; as the temperature is increased as the resistance to the expansion of the powder is increased. The work of the powder in a gun is to overcome the inertia of the shot, and to do this it presses against a certain number of inches of are
Size: 1979px × 1263px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecad, bookpublisherslsn, booksubjectscience
