Herbert "Zeppo" Marx was the youngest of the vaudeville and movie act of the Marx Brothers. He also had quite a mechanical inclination. When he left the Marx Brothers, he first joined his brother Gummo in a talent agency. Later he coinvented a wrist worn device to warn the wearer of irrigularities in heart rythms. Thousands of these were sold. He later developed a type of clamp for securing cargo in airplanes, and his cargo clamp was widely used by the Army Air Corps in WW II.