Show explosives IN VAN OF HUMAN PROGRESS mans mana most powerful slave used in many ways washington booming detonations deto nations that a century ago could have meant only the thunders of war nie are heard almost every day naw now by the innab itania of nay any sizable city they are the sounds of mans most powerful slaves explosives says a bulletin from the washington headquarters of the national geographic society carrying on their dally daily labors of peace for civilization tearing loose materials for lime and cement digging out stone for structures and roads piercing hills excavating that dams railways and factories may grow the pioneer slowly and labora ihori bously slashed its his way through na tures superficial barriers with his fix ax with much less effort the modern engineer blasts blast his way through gli mountains tumbles hills into valleys and recasts the face of the earth to his illan liking and his need an n aae ate of explosives |