English: A Visit to Chile and the Nitrate Fields of Tarapaca, 1890, page 181: "The hole into which we peered was about 7ft. deep, and for about 15ft. on either side of it the earth was heaved up and cracked in deep fissures by an explosion of the mine fired the night before. Around us were also the great blocks of costm and caliche not yet separated, which had been blown up. Two little forests of iron bars or “jumpers” were stuck into the ground near at hand t o be used by-and-by."