Rensselaer Union, Volume 7, Number 50, Rensselaer, Jasper County, 2 September 1875 — Ice-Blasting. [ARTICLE]

Ice-Blasting.

Blasting has been determined upon. Charges of three pounds, five pounds and ten pounds of ordinary gunpowder will be prepared fipr use in tin canisters, with Bickford’s fuse. If, however, the new explosive “ cotton gunpowder” should be the substance selected to carry chit this object, a small charge of about two pounds is prepared, primed with its detonator, to which is attached a short length of Bickford’s fuse. Operations are commenced from the open water and carried on toward the ship. A hole is made in the ice by means of a drill some distance from its edge, and the charge is lowered down through this until it reaches the water and is placed immediately under the ice. The fuse is ignited, a sharp explosion takes place, and the ice is shattered and sent in all directions. Men in boats, and others armed with boat-hooks and long poles, at once assail the fragments, removing them from the channel into. the open w’ater. These operations are repeated until a clear channel has been made, through which the ship is able to steam and thus effect her escape. The advantages which the “ cotton gunpowder” has over ordinary black gunpowder are numerous. It is a much more powerful explosive, its proportionate strength to common powder being as eight to one, but its great merit is said to consist in its perfect safety. If put into the fire it will burn quietly, without any explosion, nor will it explode on concussion. °- The practice of ice-blasting is not a new Invention, and had been much resorted to by the various search expeditions. Their plan was simply to lower a glass bottle, or preserved meat-tin, epntaining from two to four pounds of ordinary gunpowder, >elow the ice and explode it. The results were most satisfactory. Lieut Mecham tells us that during Capt Austin’s expedition, in 1851, a blasting party was employed for twelve days in detaching a floe from the eastern shore of Griffith Island. With 216 pounds of powder they cleared away a space 20,000 yards in length, and averaging 400 yards in breadth; this ice varied from three to five feet in thickness. The estimated weight of the ice removed was about 216.168 tons. The heaviest charge used on this occasion was sixteen pounds, lowered ten feet below five feet ice; its effect was the breaking up of 400 yards square, besides splitting the ice in several directions. The last charge would be equivalent/to two pounds of “ cotton gunpowder,*\fbut the results with the lab ter explosive would in all probability be far more effective. —From "Arctic IceTravel,” in Popular Science Monthly. Two asses are still found occasionally to make a bet the result of which is that the lose? wheels the other fora certain distance in a wheelbarrow. The latest case is reported from Baltimore, and the citi«ns neglected to shoot either idiot. • .