The manufacture of liquid oxygen and its use as an explosive

Oxygen was first liquefied in 1877, but the first record of its use commercially as an explosive was in 1899 when part of the famous Simplon tunnel between Italy and Switzerland was driven with this explosive. Owing to the difficulties of storing and using this liquid, little more progress was made until the Great War, when Germany, forced to experiment with any promising explosive because of her rapidly diminishing stocks of Chilean nitrates, made considerable headway in the technique of using liquid oxygen...Since the War liquid oxygen explosives have been used extensively in France and Germany and to a lesser extent in England, Scandinavia, Italy and the U.S. It has also been, or is being, used in at least one mining property each in Mexico (Pachuca) and Chile (Chuquicamata), and was experimented with at Cerro de Pasco, Peru --Historical, page 2-3