North Carolina History Digital Textbook Project

A technological tour of the Biltmore Estate

By Sue Clark McKendree


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This massive generator is located in the basement of the Biltmore House. (Photograph courtesy of Biltmore Company. More about the photograph)

Interpreting the development of residential electrical systems

“Electricity meant to the household what the wheel meant to moving loads” (Seigfried Giedion, Mechanization Takes Command). While electrical power already was in use in industrial applications, it did not have any real domestic applications until the advent of electric lighting. Electric light was first created by passing electric current between two carbon rods, creating a reaction that made the rods glow brilliantly, but the light was too bright for domestic use.

In 1878, Englishman Joseph Swan and American Thomas Edison made the simultaneous discovery that by using a carbon filament it was possible to create incandescent light suitable for use in the home. This electric light was first used domestically in England in 1880, and the first English country home (and one of the first private homes anywhere in the world) to be electrified was Cragside in 1881 by Swan. Smallwood Manor was probably the first new house to be electrified, in 1886.1 Most power in English homes was generated by steam or water-powered turbines at the turn of the century.2

Lord Salisbury was installing electric lights at Hatfield House at the same time as Cragside, although there were a number of problems there that had to be addressed. Lord Salisbury and his family are said to have thrown cushions at the sockets when they sparked, and his gardener was electrocuted in an unfortunate accident. “When the lights collapsed [Lord Salisbury’s] voice could be heard through the darkness amidst the general outcry of laughter and dismay, commenting meditatively on the answer this supplied to some as yet undetermined problem of current and resistance.”3

In September of 1882 Edison opened the first commercial power and light central station in America, located on Pearl Street in New York City, and by the turn of the century, Americans were experiencing the same kind of rapid growth in electrification that we today are experiencing in the availability and affordability of personal computers.

“Many Americans…got their first sense of the Edison ‘System’ and its elaborate network of conduits and cables at the World’s Columbian Exposition [1893] in Chicago - the first world’s fair to have a separate building completely devoted to electricity… in the ‘All Electric Home’ were the portents of the household’s future: electric stoves, hot plates, washing and ironing machines, dishwashers, carpet sweepers, electric doorbells, phonographs, fire alarms, and innumerable lighting devices.”4 George Vanderbilt attended the Columbian Exposition.

By 1907, only eight percent of residences in the U.S. were wired for electricity.5 Even by 1920, only about half of American households were electrified.6

Early opponents of the use of electricity for artificial light predicted that it created freckles, would cause eyestrain by damaging the retina, and subject users to an “overheated atmosphere…forc[ing] the pace of living and thus tend[ing] to the premature exhaustion of life[!].”7

light bulb

An early electric light bulb from the Biltmore Estate.

Interpreting electric lighting in Biltmore House

There are wonderful scrolled light fixtures here on the walls of the Dynamo Room, an area seldom seen by Mr. Vanderbilt and almost never seen by guests! Electric lighting was still relatively new when the house was under construction, and some of the first electrical fixtures were adaptations of gas light fixtures. Since few electrical lighting devices were available commercially, architect Hunt faced the challenge of locating or creating fixtures to use in Biltmore’s 250 rooms.

  • Hunt designed some of the light fixtures himself, including the “crowns of light” chandeliers in the Banquet Hall.
  • Many other chandeliers and sconces, including the Grand Staircase chandelier, were specially made for the house. Some were designed with motifs like the acorn and oak leaf from the Vanderbilt family crest, or the fleur de lis, symbol of the French monarchy frequently found in the chateaux that inspired the final plans for the house.
  • Many of the first electric light fixtures were adaptations of the ceiling lights and wall sconces that had been used with gas. In fact, a number of light fixtures in Biltmore House originally were made for candle or gas light but were converted to electrical power when they were installed in the House. The oldest lighting devices in Biltmore House are those that were converted from other earlier forms of power. One of the hanging lamps located in the hallway outside of Mr. Vanderbilt’s Room is inscribed with the date 1720.
  • The brass wall sconces found throughout the house, especially in the hallways, were probably among those that were available commercially.
  • Portable plug-in lamps were available as early as the 1880s, but choices were limited until after 1910, when residential wiring became more affordable.8 Many of the portable lamps in the Biltmore House collection were converted from urns, jars, or other ceramic or bronze containers, and would have been used to supplement the light from stationary floor lamps, sconces and chandeliers.
  • Originally, Edison light bulbs were used throughout the house, and several still remain in the collection. These bulbs were designed not to burn out quickly, and often broke before they burned out. “Throwaway bulbs” with short-life filaments are a more recent development. Edison bulbs also lacked the interior frosting needed in more powerful modern light bulbs. Reproductions of these original bulbs can be seen in the hanging lamps in the Main Kitchen and the Bowling Alley.

The light bulbs over the Nash generator have been “powered down” to show the degree of illumination available at the turn of the century. The first light bulbs manufactured for use in early electrical fixtures were made of clear glass with a “carbon ‘hairpin’ filament. The light from one of these lamps (c.1880s–c.1910) is considerably lower than the modern 60 watt lamp.… The [brighter] modern lamp with tungsten filament and frosted interior did not become available until the 1920s.”9

Guests may remark that Biltmore House is very dark, especially in the Tapestry Gallery, Library and Mr. Vanderbilt’s Bedroom. Explain that it is very important to remember that we are accustomed to much higher levels of light than what were available one hundred years ago, and we take them for granted. To a turn-of-the-century guest, the House would have seemed to be very brightly lit. We choose not to add more lighting in order to be historically accurate and to preserve the original ambiance of the house.

Biltmore House was wired for electricity when it was constructed and had electrical power from 1895 onward. It was one of the first private homes in Western North Carolina to be fully electrified. Plans for the electrical system included provisions for 288 lighting fixtures and 180 outlets. The electrical contractor, C. O. Mailloux of New York, estimated that 25,000 feet of wiring would be required.

  • The original electrical circuitry was designed to operate on either alternating or direct current. The advantages and disadvantages of direct (DC) and alternating (AC) current were still being debated when ground was broken for Biltmore House in 1889.
  • Since much of the equipment needed for the technological systems in the house would be located in the Sub-basement, it needed to be in place fairly quickly so Hunt and Vanderbilt settled upon the use of DC current, although they made provision for the use of AC as well.

Because direct current (DC) was developed before alternating current (AC), the first DC generators or dynamos were more affordable; because DC dynamos were direct driven, they operated more efficiently; and, finally, DC power could be stored in batteries so that the DC dynamos were not required to be kept running all the time and fluctuating needs could be met.10 Everyone seemed to have an opinion: “According to historian John J. Murray, ‘…certain clergymen and professors, and some philosophers and scientists held that God made electricity and lightening to follow a straight course and the use of alternating current, if not sinful, was at least immoral and dangerous.’”11

  • Another advantage of DC power was that that it posed much less risk of injury due to its lower voltage. Thus it was possible to install underwater lights powered by low-voltage direct current in the bottom of the Swimming Pool in Biltmore House. Located along the sides of the pool, the lights were sealed inside glass globes protected from breakage by metal cages.

At the same time that Edison was promoting direct current, rival George Westinghouse was developing his own alternating current systems. In 1877, Westinghouse created the first AC arc street lamp; however, the illumination from arc lamps was too intense for domestic use and the lamps were dirty and produced unpleasant odors. Edison believed that his DC system was much safer, and called the Westinghouse alternative “a public menace,” proposing that people begin to refer to electrocution as “Westinghousing.”12

In 1889, Edison wrote that “low-tension continuous [DC] current with a pressure not exceeding 200 v. [volts], used for incandescent lighting - is harmless, and can be passed through the human body without producing uncomfortable sensations…[220 v. DC] will force so weak a current through the human body that it barely can be detected.”13 Westinghouse countered by using 200 volts of DC current to “roast a large fresh piece of beef in 2 minutes.”14

Our archives contain clues regarding what may have been the initial configuration of the original electrical system. However, as the limitations of the first electrical systems were overcome, Biltmore House’s systems were modified and upgraded to reflect those changes and improvements. Unfortunately, many of the old systems were removed, and not much documentation is available about the evolution of the electrical systems until 1906.

The evolution of Biltmore’s electrical systems took place in a series of phases:

  1. Power was produced by a gasoline-powered engine that drove a DC generator (c. 1895).
  2. AC power was purchased from an outside source and converted to direct current via mercury vapor rectifiers.
  3. AC power was purchased from an outside source and converted to direct current via a 40KW engine.
  4. Biltmore House made the conversion from DC to AC power and no longer needed the DC generator. All power, which was by now readily available, was purchased from an outside source.

Phase one

It was Hunt’s hope that the pressure from the flow of water from Busbee Mountain would be sufficient to generate electricity, but the pressure was found to be too inconsistent to be reliable, so another system was needed. We believe that Hunt then decided to employ a single-cylinder gasoline engine “specially adapted for driving dynamo electric engines.” Hunt noted to Estate Manager Charles McNamee in 1892 that the system was to be “industrial rather than residential” in concept and scope.

  • Hunt’s original specifications called for a gas engine “of no less that 55 Horsepower Capacity.”15 The engine purchased was a 55 horsepower White and Middleton horizontal single cylinder gasoline engine that turned at a speed of 150 to 175 revolutions per minute.

According Edward R. Middleton, descendent of the man whose company made the White and Middleton engine, a February 16, 1899 article entitled “The White and Middleton Gas Engine and Shops,” published in the American Machinist, noted that “‘A 60 B.H.P. White and Middleton Engine [was installed] in the Vanderbilt Estate in North Carolina…having an output of 230 electric H.P. in a four-hour run’… Apparently this engine was installed between 1893 and 1894 …”16

  • A pulley mounted on the White and Middleton engine turned a 10-inch-wide leather belt at a rate of 3,500 feet per minute. The belt was connected to a 15 KW kilowatt (KW) generator that produced direct current for the lighting system as well as motors powering the house’s elevators and ventilators, and for charging large storage batteries used for backup lighting as well as the low-voltage rechargeable batteries. The generator was manufactured by Crocker Wheeler of Ampere, New Jersey.

Phase two

Sometime, probably between 1901 and 1906, AC power was imported into the House from an outside source. Note that there is some oral history suggesting that Mr. Vanderbilt may have owned the plant that supplied Biltmore Village and powered the Asheville & Biltmore Street Railway Company trolley cars but we have no documentation to prove this and cannot say for sure that he did.

When Charles Waddell came to work here in 1901, he negotiated a contract with the Asheville Electric Company to buy AC power at night. The AEC agreed willingly because it had recently purchased the Asheville & Biltmore Street Railway Company and had excess generating capacity once the streetcars stopped running each night.

  • Mercury vapor rectifiers were first used to convert this AC power to DC for use inside the house. These rectifiers were originally mounted on the wall to the left as you enter the Generator Room. You can see the holes where they were mounted.
  • The direct current produced by the mercury vapor rectifiers powered the house’s DC electrical systems. Excess power charged a system of large Gould storage batteries originally located in the Transformer Room. Each battery had a storage capacity of 2,000 ampere-hours (one 100 watt light bulb uses approximately 1 ampere). These batteries stored excess power for later use whenever it was needed in the House.

Phase three

At some point, probably around or just after 1906, Waddell began to use the imported AC power to drive a large three-phase AC electric motor which in turn drove a 40 KW DC generator to which it was attached (the smaller engine now seen in the Dynamo Room). We do not know exactly when this engine was installed, but it definitely was not part of the original electrical system in 1895. Power in excess of what was being used in the house at any given time also was stored in the Gould batteries.

  • It would make sense that the rectifiers were no longer needed after the installation of this 40 KW engine, since the AC power coming into the house now drove the generator that replaced the rectifiers.
  • During the day Biltmore House continued to generate some of its own power in order to supplement what was stored in the Gould batteries. In 1906, Waddell added a 25 HP gas-powered, two-cylinder Nash engine, the larger engine now in the room, and a 15KW generator. The Nash engine was water-cooled and exhaust was vented to the outside. The fuel tank also would have been outside the house.
  • Since the Nash engine most likely was used as a back-up when power stored in the Gould storage batteries was nearing exhaustion, it probably need to be started manually. It would have been the responsibility of the Dynamo and Transformer Room staff to monitor the level of power left in the batteries and start the Nash engine before stored power ran out.

Phase four

Eventually, all of Biltmore House’s power needs were satisfied by the local power company and the Nash engine was used only for emergencies. Biltmore House began the conversion to AC power sometime between 1915 and 1918.

Interpreting the main circuit board

Electrical current from the generator and storage batteries was fed through the main switchboard. Measuring seven by sixteen feet, it was made of three slabs of solid marble (chosen for its insulating properties) and had brass trim.

  • The power produced by the complex AC/DC system was transmitted to this switchboard. Here the flow of power was monitored, measured and distributed to the direct current motors, the light system, and the batteries.
  • The center panel had switches that controlled the flow of DC power for the elevator and dumbwaiter motors and the refrigeration pumps, as well as current for the 49-circuit lighting system, the heating system and telephones.
  • The largest switch was the main shut–off to the house. Point out the individual feeder switches.
  • If the generator was not running, knife switches turned on the power from storage batteries once located on the wall near the door.
  • The panel on the left was for alternating current, while the one on the right controlled the use of the storage batteries.
  • The original wiring came out the back of the switchboard and extended through the Boiler Room. The wiring was encased in ¾ inch brass conduit with a layer of insulating material inside. We do not know what the insulation material was.
  • A similar circuit board can be seen at The Elms in Newport.
  • There is a resuscitation chart on the wall by the door, characteristic of George Vanderbilt’s concern for his employees.

Mssrs. Woody and Kimberly are noted in turn-of-the-century correspondence as having worked here as electricians. Andrew Jackson Garland was hired during the 1920s to assist with rewiring in Biltmore House. He recalled getting lost coming out of the Sub-basement and having to retrace his steps to the Dynamo Room to find his bearings.17

  • Until April of 1990, the original marble switchboard was still in use. It was converted to a modern breaker system (located in the Transformer Room) for the safety of guests and because the original system had become inadequate, having no room for the addition of new circuits. A modern generator now provides power to the house if city power is lost; it kicks in automatically, and the house functions on somewhat reduced power until city power is restored.
  • Systematic rewiring began in Biltmore House in the 1980s to bring the house up to contemporary electrical codes.
  • Large feeder cables carried power from the generator/storage batteries/AC source to the electrical panels found behind the oak doors on the walls throughout the house. Smaller branch circuits carried the power from the electrical panels to the lights and other electric appliances in the House.
  • Feeder cables → Electrical Panels → Branch Circuits → Lights
  • We still use all of the original feeder cables that lead to the electrical panels.
  • However, we have replaced many of the branch circuits.
  • The fact that the original wiring was encased in brass conduit made the task of rewiring at least a little easier.
  • In the original panels that we still use, the original fuse wire has been replaced with cartridge fuses.
  • We stopped using the main circuit board in 1990 for two reasons.
    • First, we were concerned about the safety of guests coming to the Sub-basement on tours. Second, we have added many new lights in the house, particularly in hallways and on staircases, again, out of concern for guest safety. These lights required additional circuits that could not be accommodated by the original circuit board, and generated much new wiring in addition to what was originally in place.
    • Second, we have added many new outlets. Since electricity was so new in 1895, there were very few appliances that required outlets, and most lights were direct-wired. There were 180 floor outlets in the house, but not nearly enough to accommodate our needs today for fans and other electrical appliances.

Interpreting the lightning arrester

Lightning strikes were always a potential problem for six-story Biltmore House, which sits high on the ridge overlooking the French Broad River.

  • Lightning rods were installed in the highest parts of the roof. The wiring for these rods converged into the heavy wire above the arrester.
  • The 3-phase “Electric Lightning Arrester ”(patent date June 30, 1908) could ground up to 7500 volts of electricity.
  • We do not know what the purpose was of the apparatus above the arrester. Rick Conard speculates that it might have allowed the current to arc from one point to another, thus losing power, until it was directed into the arrester itself.
  • Today we still use the same system of lightning rods. However, in order to meet contemporary electrical codes, lightning is now grounded through the service panels here in the Sub-basement.


Show them the conduit for the wires going into the Transformer Room.