 During the 1890s, Entz became fascinated with the development of the automobile, and by 1897 he was working as a chief engineer at the Electric Storage Battery Company in Philadelphia, Pennsylvania.In 1897 this company introduced an electric-powered cab to the streets of New York and Philadelphia.It was while working for the Electric Storage Battery Company that Entz designed a gasoline-powered automobile with an electric drive transmission, and this was built as the prototype Columbia Mark IX by the Pope Manufacturing Company.