"Benjamin F. Leavitt of Traverse City, Michigan, dives on the SS Pewabic which sank in 182 feet (55 m) in Lake Huron in 1865, salvaging 350 tons of copper ore. In 1923 he went on to salvage the wreck of the British schooner Cape Horn which lay in 220 feet (67 m) of water off Pichidangui, Chile, salvaging $600,000 worth of copper. Leavitt's suit was of his own design and construction and he had previously dived to 361 feet (110 m) in it in Lake Michigan. The suit used manganese bronze to resist corrosion and weighed only 350 pounds (160 kg) complete, which reduced to 75 pounds (34 kg) underwater, and was lined with sheet rubber for insulation. The arms and legs were constructed of flexible copper tubing with ball bearing joints at knee and elbow, while the helmet had four 0.5 inches (13 mm) windows of shatterproof glass and was equipped with a telephone. The most innovative aspect of Leavitt's suit was the fact that it was completely self-contained and needed no umbilical, breathing mixture being supplied from a tank mounted on the back of the suit. The breathing apparatus incorporated a scrubber and an oxygen regulator and could last for up to a full hour."