Perhaps one of the earliest styles of clocks that influenced the first true digital timepieces were Plato clocks. These pieces were small cylindrical-shaped objects, similar to a lantern. Inside the glass display were small digital cards with numbers printed on them, which flipped as time passed. The spring-wound Plato clocks were introduced at the St. Louis World Fair in 1904, produced by Ansonia Clock Company. Eugene Fitch of New York patented the clock design in 1903.