I read with interest the article in last year’s August/September issue that traced the history of air conditioning. Certainly Willis Carrier was the “Johnny Icicle” who was responsible for the cooling of America; but 1 was interested to see that the story does not describe a fantastic and forgotten public utility that cooled off customers well over a decade before Carrier set up his first installation.

In St. Louis, Denver, and Atlantic City at the end of the nineteenth century, it was possible to order refrigerant pumped to your business through street mains. Breweries, meat-packers, hotels, restaurants, and even one farsighted theater owner took advantage of this safe, convenient, economical method of cooling.

The artificial manufacture of ice was perfected in the early 1870s, but much of the cost of ice, manufactured or natural, lay in its delivery to the customer. Across America inventors set about trying to do away with the iceman—and even the ice itself—by building cooling systems in several different cities. Their efforts ended in costly failure, but they pointed the way for a group of entrepreneurs named Starr, Thornburgh and Branson.

These men studied the cooling equipment of the day—ice machines that furnished refrigerant to cold-storage warehouses adjacent to them—and concluded that the next logical step would be to supply refrigerant to far-flung users through a system of mains.

They formed the Colorado Automatic Refrigerating Company, built a plant in Denver, and put it into operation in March of 1889. It consisted of a thirtyton ice machine, two miles of mains, and a cold-storage warehouse with a capacity of fifty thousand cubic feet. For the refrigerant, they chose ammonia: it was nonexplosive, nonflammable, and its sharp odor would give immediate warning of any leak. The one-inch wroughtiron main ran to twenty-nine separate “cooling boxes.” Each connection had a valve with a 1/64-inch opening that let the coolant into a grille of 1½-inch pipes on the room’s ceiling. The ammonia traveled to the valve in liquid form at room temperature; once inside the large coil, however, it expanded to its gaseous state and absorbed heat from the pipe, and thus from the room—a radiator in reverse. The far end of the coil was connected to a three-inch return main.

The service was a success from the start. Before long the partners could replace their original pipe conduit of rough wooden planks with vitrified clay, and all the cast-iron fittings with more costly wrought-iron ones. They added a third pipe to the system as a spare for emergencies: an arrangement of valves let it temporarily bypass any section of the main line that needed repairs without interrupting service.

The promoters claimed many advantages for their system: customers gained one-third more usable space, which formerly had been taken up by ice; temperatures could be maintained within two degrees and held as low as twenty-five degrees Fahrenheit; the