Jonas Chickering made several major contributions to the development of piano technology, most notably by introducing a one-piece, cast-iron plate to support the greater string tension of larger grand pianos. He also invented a new deflection of the strings, and in 1845 the first convenient method for over stringing in square pianos. Instead of setting the strings side by side, the company introduced substituting an arrangement of the string in two banks, one over the other. This not only saved space but brought the powerful bass strings directly over the most resonant part of the sound-board, a principle used to this day in the construction of all pianos, both grands and uprights.