Although many technological systems appeared on the urban landscape in the late nineteenth century, historians of technology have largely focused on electrically-related system, orbiting around telephones, telegraphs, and light bulbs like so many bugs on a hot summer night. Although sometimes very illuminating, such studies necessarily limit themselves to a small portion of the rich urban technological landscape. As a small corrective to this trend, I present here an episode in the history of thermal heat and power distribution, whereby a large number of buildings are supplied with steam or hot water from a central heating plant.

District heating, as it is now called, has a long and rich history, with one system in France having been in continuous operation since the early fourteenth century. Cornelis Drebbel, who introduced the thermometer and telescope into England, proposed to install a district heating system in London in the early seventeenth century, to permit inhabitants of that already smoky city to cook their food and heat their houses without burning wood or coal. Boulton and Watt installed district steam systems in the late eighteenth century, and many others were proposed and installed prior to 1877, when Lockport, New York inventor-entrepreneur Birdsill Holly established the first successful commercial district heating system, selling steam to individual consumers for heating, cooking, power, and fire protection.

Holly, widely known at the time for his system of direct pressure water supply, developed a steam system that had much in common with his water supply. In particular, he did not return condensed steam back to the boiler plant through a condensate return pipe, which he believed to be very troublesome and of marginal economic value. His Holly Steam Combination Company installed about 30 steam systems between 1877 and 1882, including a commercial system serving downtown Denver that is still operating. In 1882 the company was purchased by the American District Steam Company, which had been formed by investors associated with Standard Oil who had earlier purchased the rights for the Holly system in New York City and wanted to control the entire district heating marketplace.

The system of the New York Steam Company was installed in Manhattan under the direction of Charles E. Emery, a noted civil and mechanical engineer. Emery ignored many of Holly's ideas, and chose to include condensate return pipes not so much to increase plant efficiency as to reduce purchases of expensive Croton water. In this picture from Scientific American showing the pipes, the larger steam supply and smaller condensate return are clearly shown. Despite owning Holly's patent rights, the New York Steam Company had three competitors who also obtained heating franchises for Manhattan. Two used steam, while the third used Willam E. Prall's superheated water system. Prall held more than two dozen patents for steam engines and railway signals, believed that superheated water was a superior thermal distribution medium.

Water, of course, boils at 212° F (100° C), but only at standard atmospheric pressure. If confined in a pressure vessel, water can be heated to much higher temperatures, which Prall called superheated water. Angier March Perkins had heated buildings with water at 500° F or even higher since the 1830s, and his apparatus was widely used in Britain and France, but only a few examples are known in the United States, including the New York Customs House and the Philadelphia Penitentiary. The Perkins system was very simple, with a completely sealed piping system and had no moving parts, depending on convection to create flow. Many Perkins systems were in operation until well into the twentieth century. To avoid the system constraints of using convective flow, Prall used steam-driven pumps to force 400° F water through a network of underground mains. Prall installed a small system on the Upper East Side of Manhattan, which was demonstrated to the American Society of Civil Engineers at their annual meeting in 1880. After inspecting the system, the engineers were treated to an elaborate meal that had been prepared entirely with Prall's superheated water stoves. Like Holly, Prall intended to provide power and cooking services with his system.

The engineers, although well-fed, did not lead to financial support, and the better financed American District Steam Company was alone in busily digging up streets all over the United States and Canada. Not all of their systems were successful, however, as a few went broke from financial and management problems. Some technical problems also appeared, such as exploding pipes at the Holly system in Lynn, Massachusetts in 1882 which received wide publicity and led to some sales difficulties. The Philadelphia City Council particularly cited the Lynn explosions in failing to act on a heating franchise the following year.

Prall, having failed to obtain support in America, went to Europe where he obtained patents for his system and attempted to interest European investors. Success apparently eluded him there as well, however, for he was back in Washington in 1884, where he became proprietor of an apartment house two blocks north of the White House, although he continued to operate a second small demonstration system under the name Washington Heat and Power Company. In the meantime, the American District Steam Company had installed systems from Salem to San Francisco.

There the matter may have rested, but in early 1883 Samuel M. Bryan returned to Washington from Japan, where he had spent ten years starting up the Japanese postal system. Bryan was elected president of the Chesapeake and Potomac Telephone Company in November 1883 and at some point became familiar with Prall's system, which he introduced to his old friend, Theodore Newton Vail, with whom he had served in the U.S. Post Office in the early 1870s. Vail had become general manager of the Bell Telephone Company in 1878 and also the first president of AT&T upon its founding in 1885. Vail had accumulated some wealth from these positions and created stock companies as a hobby. Failing health forced him to give up his telephone positions, but he was naturally attracted to the benefits offered by the Prall system. He was cautious enough to engage not one but two prominent engineers to investigate the system. Benjamin F. Isherwood, Chief Engineer of the U.S. Navy and perhaps the most prominent mechanical engineer in the country, reported that "Its safety, practicability, and efficiency admit of no doubt."

When the second engineer also reported favorably, Vail and Bryan incorporated the National Superheated Water Company in December 1886 with 100 shares at $100 each, for the purpose of installing the Prall system in several cities. They hired Arthur V. Abbott, former assistant engineer on the Brooklyn Bridge, to be their chief engineer. Boston was first on their list, and the Boston Heating Company was formed in December 1886, with streetcar magnate Calvin A. Richards as president and Lester Leland treasurer. In February the company petitioned Boston's Aldermen for a franchise to lay pipes in and under streets between that part of Boston proper north of Kneeland, Eliot, Providence and Arlington streets. The Aldermen considered the matter and voted to visit Washington to examine the Prall system operating there. In March they voted to grant a franchise, but only on an experimental basis in the area bounded by Atlantic avenue, Sumner, Devonshire, Washington, State and Broad streets. Boston Mayor Hugh O'Brien vetoed the bill, based on the opinion of the Boston city engineer that it was not only inadvisable to install such a system, but "extremely dangerous to the public, as well as unremunerative to the stockholders." New York Steam Company engineer Charles Emery also found time to write Boston officials about the evils of superheated water, but the Alderman unanimously overrode the veto and granted the franchise, much to the surprise of the local newspapers.

After receiving the franchise, detailed plans were prepared for the installation of the Boston system and the first of 13,000 feet of pipe went into the ground on 20 July 1887. Engineering News reported in August than "40 or 50 applications a day for service are coming in." The pipes underwent extensive testing before heat and power service began late that year. Even before the first pipe was installed, the $200 a share was offered Boston Heating stock and Vail was forced to buy out Bryan's share to maintain control. While the Boston system was being installed, Vail formed other companies and obtained franchises in Philadelphia, Rochester, Newark, and Brooklyn, and also purchased the Washington Heat and Power Company's system.

By the end of 1887, Vail had invested over $200,000 of his own money, but construction costs proved to be nearly twice the estimates and Vail was forced to seek outside investors. The authorized capital stock, which had already been raised from $10,000 to $1 million, was increased yet again to $250,000 in February 1888. Blocks of stock were sold in America, and Vail also traveled to England in the spring and sold £50,000 (about $250,000) to British capitalists.

Despite the heavy expenses, the Boston company was apparently prospering and Vail joined his wife and son in Venice the following winter, as Boston winter's were considered too harsh for his uncertain health. At the close of 1888 a dividend of 12% was declared, but within weeks it was clear that the plant had grave technical defects. Vail hurried home and was told that $200,000 was required to correct the faults. Vail returned to England to issue bonds, but the English investors refused to provide capital to carry on the enterprise. Vail ended up borrowing the required sum with a personal guarantee and wrote a stockholder that "This will take us out of the soup, or put me into it-one or the other."

The repairs proved to be ineffective, however, and the system limped into its third winter. Vail's health was broken. He had been forced his sell his yacht, his paintings, and his home in Boston, although he was able to retire to his Vermont home in September 1889. Abbott and others tried valiantly to salvage the system, but were forced to suspend service on 6 November 1889. The ensuing litigation was unpleasant, to say the least. Drexel Morgan held a mortgage of $750,000 with the franchise itself as collateral, but several stockholders brought suit, claiming that a franchise cannot be offered as collateral without an act of the legislature. The British investors sued Vail and other officers for fraud, claiming that they materially misrepresented the financial state of the company, including paying the 12% dividend not from profits but invested funds.

Vail, of course, was no swindler, and made great efforts to pay back his obligations, including paying large sums of money to those for to whom he felt "directly responsible for buying the stock." The plant and system were sold for scrap in late 1892 and the whole matter was soon forgotten.

A short technical description of the system will serve to highlight the specific problems that proved fatal to the Boston Heating Company. The system theory was rather simple and not unlike the earlier and very successful Perkins system. Very hot water was delivered to a customer, where it was used directly for heating, flashed into high pressure steam for power purposes, or low pressure steam to supply existing steam heating apparatus. The water was then returned in a larger return pipe. This picture of the Boston Heating Company's supply and return pipes shows the four-inch supply pipe and eight-inch return pipe, which is opposite of the steam supply pipe shown earlier, which have a large supply pipe and small return.

It would be reasonble to expect problems with the supply pipe, which carried water and high pressures and temperatures, and great care was taken in engineering and installing all of the pipes to meet those conditions. The system failed, however, because of corrosion in return pipe, which simply rusted away. At the time it was thought that the alternative heating and cooling of the return pipe was allowing the collection of outside moisture and causing rusting on both the inside and outside of the pipe. Today we know that this condition only causes corrosion on the outside of the pipe, while the inside of an atmospheric or "open" return is corroded by oxygen. The Perkins system, which was completely closed, allowed no oxygen into the pipe, and thus no rust could form. Both the supply and return pipe in a Perkins system was maintained above 212°F, meaning that small amounts of free moisture contacting the outside of the pipe would be boiled away fairly quickly.

A steam system requires much less mass to deliver a certain amount of heat, and can therefore operate successfully, if slightly less economically, without returning the condensed water. A water system, however, requires a much higher mass flow to deliver the same quantity of heat. Supplying a 25 horsepower steam engine with 60 psig steam, for instance, requires 8100 pounds of superheated water per hour to generate the required 876 pounds of steam to drive the engine, or more than nine times the mass than a steam system would require. If the water did not return to the boiler for reuse, the costs of replacing and reheating the water would be enormous, as the Boston Company discovered.

The failure of the Boston Heating Company marked the end of high temperature hot water in the United States for sixty years. Engineers in Europe, however, quickly pinpointed the problem and simply kept the entire system closed. Where steam was required, instead of flashing the superheated water a heat exchanger, as Perkins had done in the 1830s. High temperature hot water district heating came into wide use through Europe and the Soviet Union between World War I and II, which very satisfactory results. During the Strategic Bombing Survey of Germany after the war, Air Force engineers were surprised to discover that bombing had little effect on high temperature water systems, which were quickly repaired and restored to service. Recognizing the value of this technology, the Air Force installed a high temperature water system at Loring Air Force Base in Maine in 1950. For the next two decades this became the "appropriate technology" for new district heating applications. Hundreds of systems were installed in college campuses and military bases, most of which have operated quite successfully, although high maintenance costs for valves and pumps has now recently caused many to be replaced with low temperature water systems.

Vail, who never doubted that more opportunities would arise, regained his lost fortune many times ago and in 1907 was again elected president of AT&T. The Boston Heating Company was just one of the business failures that he took with calmness before moving on to the next adventure.

Arthur V. Abbott abandoned the thermal supply field for an electrical career and wrote several books on telephone and electric construction before his death in 1906 at the age of 51.

Although the Boston Heating Company has disappeared, some of its underground pipes were purchased by Bell Telephone and as late as the 1930s were used as conduits for telephone wire. If kept dry, they may still be doing so.

Despite the failure of the Boston Heating Company, district heating did not disappear from Boston. The ability to use exhaust steam from engines to heat buildings had been used as early as 1811. The Holly system in Lynn and another in New Haven delivered high pressure steam to power customers, then delivered the exhausted steam to other customers for heating.

This system grew rapidly in the 1920s and is now one of the largest systems in the US. The system was sold to Catalyst Thermal Energy Corporation on February 6, 1986 for $32.5 million.  It was later bought by Trigen and is now owned by Vicinity Energy.

History of District Heating

© 1995 Morris A. Pierce