American Carbolite

American Carbolite. (Image: Duluth Public Library)

The American Carbolite Company, of Duluth, is not only the largest of its kind in the world, but its electrical equipment is not outclassed by any manufacturing plant in the United States.

Three of the great essentials of existence are light, heat and water. With a perpetual supply of these provided for, the human family would have no need of taking thought for the welfare of future generations. In past ages even the temporary or partial suspension of nature’s light, which occurs at times in midday, resulted in great annoyance, inconvenience and financial loss, while the fact that for a considerable part of each twentyfour hours the light of day is regularly withdrawn has been a perpetual inspiration to man’s inventive skill to contrive some means for controverting the effect of this seeming neglect on the part of Dame Nature. Many makeshifts have been resorted to from time to time, but it remained for the present generation to reach the acme of discovery in the way of artificial light. The light question has been settled for all time by the introduction of carbolite, from which acetylene gas is manufactured, which for quality, reliability, economy and safety is far in advance of electricity and gasoline as an illuminant, without the annoyance and danger of smoke and heated rooms nor the expense of mantels and chimneys. The discovery of carbolite was a great boon to humanity, for it brings light to millions who formerly enjoyed only the illumination of the smoking tallow dip or the foul smelling kerosene lamp.

This has been made possible by the inventive skill of Herman 533  L. Hartenstein, who discovered the secret of making from limestone and coke calcium carbide, the trade name for which is “carbolite.” This produces a soft, white light, more beautiful and intense than the sunlight, yet free from glare, heat or odor.

Hartenstein’s father was the superintendent of a steel mill in West Virginia, and it was there that he gained his first lessons in practical chemistry. Here he began a series of experiments for the purpose of devising some method of utilizing the slag piles or refuse of the smelters and blast furnaces, and these experiments resulted in the discovery of the art of making calcium carbide from limestone and coke. The result of this was the organization of a company and the building of a factory at Constantine, Mich., for the manufacture of carbolite. The factory was unable to keep up with its orders, and a larger plant became necessary. Various locations were looked over, but it was finally decided that Duluth offered the ideal location as to trade possibilities and as a distributing point by rail and water, while the Great Northern Power Company offered an exceptional opportunity for obtaining the necessary electrical energy. A site comprising nineteen acres was obtained and the work of constructing the necessary buildings begun. Today the plant consists of twelve expansive buildings. which cover a ground floor space of nine acres. The main storage building, 600 feet long, has a capacity of 25, 000 tons of raw material. The electric furnace building, 400 feet long, contains twenty-one electric transformers and twenty-one electric furnaces. The preheating building contains two immense furnaces, seven feet in diameter and 100 feet long, which, with the other equipment, makes the plant a world beater. Here over 200, 000 pounds of carbolite is produced daily, which will produce acetylene gas equivalent to 12, 000, 000 cubic feet of coal-water illuminating gas.

In the making of carbolite limestone is ground in a great crusher to a fineness which makes it practicable to handle, and is then conveyed to the preheating furnace. These furnaces are about six feet in diameter and 100 feet in length, and they are revolved at a speed of about one revolution a minute. They are so inclined that the limestone, introduced at the upper end, will move gradually toward the lower end. At the lower end of the furnace the limestone is subjected to the intense heat of a jet of a variety of water gas termed “producer gas, ” and is raised to a white heat. At this point it drops out of the furnace, and after being weighed is mixed with coke, which is nearest the pure form of carbon which it is practicable to use, and then dropped into steel cars and carried to the electric furnaces, where the process is completed. This first heating drives off carbonic acid gas, leaving a combination of calcium and oxygen, and when this compound is mixed with carbon in the form of coke the oxygen combines with the carbon to form carbon dioxide, and its place is taken by an atom of carbon, forming the desired compound of calcium carbide, or carbolite.

The ground covered by the factory buildings and yards has a perfect railroad system for handling the transportation of the raw material and shipping out the manufactured product. The limestone, on being received at the works, is carried by great chain-belt conveyors into the 600-foot storage house, and the coke supply is handled in the same way. The limestone that is put to immediate use is taken from the conveyor automatically and put through the crushing machines, and again transferred by the same conveyor system to the preheating furnaces, which, with the gas producers, occupies a building of steel and reinforced concrete. Turning slowly, it permits the material that is fed. to it to proceed by gravity through its length. The limestone is fused by the fierce heat of the producer gas, automatically weighed, mixed with coke that has been crushed, and sent in steel cars over a tramway to the electrical furnace building.

All of the machinery is operated by electricity. In the electric furnaces the product is subjected to intense heat discharged by wonderful electrodes, so nicely adjusted over the hearths that the heat is equably diffused, and consequently no loss of material ensues by cooling on the hearth, the product being carried away from the furnace on a tramway system, after which it is moulded into ingots. These ingots are carried to a crusher and broken up ready for packing in steel drums and smaller cartons, in which they are supplied to the trade or the consumer. Drums contain 1, 100 pounds of the carbolite, and are used in larger installations. The smaller packages of two and ten pounds each go to the smaller consumers or portable lamp trade.

It requires no expert knowledge to produce acetylene gas from the carbolite, and anyone can take care of a plant with as much ease as the chauffeur cares for his lights. The carbide is put up into a receptacle containing water and permitting room for the storage of a quantity of the gas, which is generated at  once. The gas may be applied to a burner attached to the generator piped for any distance, as ordinary gas is, the size of the generator being proportioned to the supply of gas required.

The whole field of illumination, from the single light on a vehicle to the lighting of a town, is covered by the same simple process and its amplification. Acetylene is the purest and safest of all illuminating gases. It consists, approximately, of 93 per cent carbon and 7 per cent hydrogen. In the ordinary gas there is present carbon monoxide in quantities ranging from 13 to 15 per cent, while acetylene gas contains no carbon monoxide. A pound of carbolite will produce over five cubic feet of acetylene gas, each foot of which equals in illuminating power twelve feet of ordinary gas. A burner consuming one-half a foot of acetyllene gas per hour will give a twenty-five candle power light, while it would take about six feet of ordinary gas to produce the same result.

A reorganization of the Carbolite company took place in 1908, at which time local capitalists obtained complete control of the company’s affair and have since conducted it successfully. The company gives employment to about 300 men. Its officers are John A. Sinclair, treasurer, and Miss Florence Emanuelson, secretary.

These officers, with C. M. Van Norman, Lillian I. Feetham, W. D.Bailey, Oscar Mitchell and M. A. Alworth, constitute the board of directors.


  • Woodbridge, Dwight and John Pardee, eds. History of Duluth and St. Louis County Past and Present Vols. 1 – 2. C. F. Cooper & Company, Chicago: 1922.