41 G ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



pose of great utility, viz., as an aid in boring artesian wells. 

 The owner of a large estate wanted water for bis dairy, and 

 commenced boring for it. For 80 to 90 feet no difficulty oc- 

 curred, when a stratum of flint was struck, so unyielding that 

 it appeared advisable to give up the enterprise ; but, as a last 

 resort, dynamite was tried with the best possible result. 

 Two pounds of dynamite, in a flask provided with isolated 

 conducting wires, were lowered down the well-cleaned bor- 

 ing to its bottom, upon the impenetrable flint, and then ex- 

 ploded. The percussion was barely perceptible at the sur- 

 face of the ground, but the water in the bore was thrown up 

 many yards. The bore, however, filled again immediately, 

 and it became evident that not only the flint layer was 

 pierced, but also that strata rich in water were opened, so as 

 to render further boring unnecessary. Two more charges 

 were exploded, and the flint at the bottom was found to be 

 broken into fragments, while the tubing was entirely unin- 

 jured. The well now yields daily an ample supply of water. 

 14 <7,CC.,i.,47. 



COMPARISON OF FORCE OF STEAM AND GUNPOW r DEE. 



In comparing the power of steam and of gunpowder, it is 

 said that the force exerted by the expanded gas in the ex- 

 plosion of a charge of powder, in a three hundred pound 

 Woolwich gun, is equal, at some instant during the two hun- 

 dredth part of a second, to nearly three million horse power. 

 12 A, November 10, 35. 



EXPERIMENTS WITH COMPRESSED GUN-COTTON. 



The remarkable experiments by Mr. Abel, of Woolwich, in 

 regard to the effect produced by compressed gun-cotton, 

 when simply laid on or pressed against the surface of bodies, 

 and the various applications suggested of this new explosive 

 agent, are doubtless familiar to our readers. A series of ex- 

 periments has lately been made by the officers of the Royal 

 Engineers, at Chatham, to determine more particularly the 

 comparative effect of gun-cotton and gunpowder, and it 

 was found that when two hundred pounds of gunpowder 

 were laid against a double stockade of beams of timber four- 

 teen inches square, three feet six inches apart, and sunk three 

 feet in the earth, a large gap was made in the front stockade, 



