American designer MacDuffy constructed the first suit to use ball bearings to provide joint movement in 1914; it was tested in New York to a depth of , but was not very successful. A year later, Harry L. Bowdoin of Bayonne, New Jersey, made an improved ADS with oil-filled rotary joints. The joints use a small duct to the interior of the joint to allow equalization of pressure. The suit was designed to have four joints in each arm and leg, and one joint in each thumb, for a total of eighteen. Four viewing ports and a chest-mounted lamp were intended to assist underwater vision. Unfortunately there is no evidence that Bowdoin's suit was ever built, or that it would have worked if it had been.