This building housed steam generators, an air compressor, an electric generator, and other equipment used to power quarry operations. In the quarry’s early days, work was done by hand, but the later use of power tools greatly increased efficiency. Compressed air powered the drills, crusher, elevator, and sawmill, while electricity powered the hoists for the derrick cranes. Most quarrying equipment of the time could use either steam or compressed air, but air was considered superior because it was safer and could be sent far from the compressor without losing power as it cooled. Remote boilers supplemented the power house, where coal heated water tubes to vaporize water into steam, and air lines extended hundreds of feet from the compressor. The building had to be very large to hold the massive equipment.