In 1840, The Cocheco Mfg. Co. switched from wood to coal to fire its boilers. From their inception in 1815, only wood had been used in the factories and most of the north side of Third Street served as the huge company woodyard. When the B&M Railroad reached Dover in 1842, the woodyard was abandoned and coal began arriving on trains as well as in schooners. By 1887, the boiler house was using 20,000 tons of coal each year in 45 boilers.
