The earthquake-making instrument was part of a project sponsored by the Earthquake Engineering Research Institute and under the direction of George W. Housner and Donald Hudson. The machine weighs close to 500 pounds, including its 1.5 horsepower motor. Shaking is produced by a pair of 20-inch swing boxes that counter-rotate unbalanced amounts of lead weights. The machine was designed by Dino Morelli, while Thomas Caughy developed the electrical design. Engineering and Applied Science.