Page:Popular Science Monthly Volume 90.djvu/907

 Popular Science MordJdy

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��Stopping Mexican Bullets with Sand-Filled Oil-Cans

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��''HEX residents of Naco, x\rizona, a border town, began to barricade the walls of their homes against Mexican bullets, one man made a visit to the town dump and obtained every' available five-gallon coal oil can. These he filled with sand and then built a wall with them against side of his house facing tl Mexican line, about tv^-o hundred yards distant. About one hundred and fifty of the cans were re- quired but he had little difficulty in finding this number; for Naco, like hundreds of other West- ern towns, is a place where coal oil is not sold "loose," but is obtaina- ble only in square tins holding five gallons each. When the task was completed the man had the equivalent of a solid wall of sand a foot thick along the side of his home. During a battle fought on the Mexican side of the town in Janu- ar>% 19 1 5, when the Carranza forces holding Naco, Sonora, were attacked by Yaqui Indians, hundreds of bullets came across the line and this unique barricade stopped all that came its way. The homesteader carefully repairs and refills any of the cans that become damaged.

��Drilling Holes in Concrete with a Crank- Operated Spring-Hammer Drill

RILLIXG holes in concrete has always

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���The new type of crank-operated spring-

��hammer drill used as a

��quickened by the introduction of a new type of crank-operated spring-hammer drill which delivers fifteen hundred blows a minute and uses hollow drills instead of star or fluted drills. Hence all the material removed is pulverized or ham- mered to a dust. The device may be used as a breast-drill for holes in vertical walls or for holes in ceilings or

beams. \ The drill consists of a hollow barrel in which reciprocates a piston or hammer against the compression of a spiral spring at the handle end. The movement is produced by a ratchet- wheel turned by two hand cranks. As the ratchet is revolved the piston carrying the drill at its free end is forced back against the compression of the spring. As the ratchet tooth escapes, the piston jumps back under the expanding coil spring. The faster the ratchet is turned the greater the num- ber of blows transmitted to the drill, which is rotated in the usual manner. The ten-

���A solid wall of sand-hlled oil-cans forming a barricade a foot thick along the side of the house facing the Mexican line

��breast drill

its socket in sion of the spring may be adjusted to vary the force of the blows by means of a collar bearing against the handle end of the spring, this collar being moved in or out through the medium of a threaded bolt and outside thumbscrew.

The device has a telescoping extension for drilling holes in ceilings and the under- sides of beams. It has found a ready market among the firms mak- ing and installing sprinkler systems on account of the ease with which the holes are drilled for the supports to hold the sprinklers in place. Plumbers and heating and electrical contractors make use of it for drilling in con- crete, brick walls or stone for expansion bolts, pipe hangers and the like.

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