The first fire extinguishers were of the "annihilator" pattern, so arranged in a building that when a fire occurred carbonic acid gas was evolved, and, if the conditions were right (as the mediums say), the fire was put out. It worked very nicely at experimental fires built for the purpose, but was apt to fail in case of an involuntary conflagration. About the year 1867 a patent was granted to Carlier and Vignon, of France, for an apparatus in which water saturated with carbonic acid gas was projected upon the fire by the expansive force of the gas itself. As the apparatus was portable and the stream could be directed to any point, it was obviously the desideratum needed. Mr. D. Miles, of Boston, purchased the American patent, and subsequently sold the territory, exclusive of New England, to the Babcock Co., who, at the time, had a crude apparatus of their own. The first machines sold under the new patent were filled with water and loaded with cartridges of dry acid and bicarbonate of soda--the cap screwed down hastily, and, as the chemicals dissolved, the gas was generated, the pressure raised, and the water charged by absorption. The pressure of some 80 pounds was sufficient to project a stream 50 feet or more, and the machine was set upon the shelf so as to be ready for any fire that might occur. In many cases, however, the pressure escaped after a short time, and the machine when needed was found to be useless.

The most important step in the evolution of the modern extinguisher was the adoption of a device for mixing liquid acid with the soda solution, by the turning of a handle or screw, after the alarm was given. This was a practical machine, and proved of such value that an immense business was built up. The result of this prosperity was the development of new companies with new devices for accomplishing the same result, which were successfully offered to the public with varying success.

As these were direct infringements upon the patent rights acquired by the Babcock Company, their encroachments were resisted in the courts, and much money was spent in the effort of the company to sustain their rights, including the purchase of the patents of several rival machines that possessed real merit or whose business was worth controlling. Among these purchases was the right and good will of the "National" Extinguisher Co., who used an acid cartridge of glass, the acid being liberated by breaking the glass. This feature, united with important improvements in general construction and the use of a peculiar glass bottle instead of a tube, is the Babcock machine of to-day, the combination making the simplest and most effective and reliable apparatus ever built. In the meantime, an investigation before the courts brought out the fact that the French patent was antedated by an American invention, for which a patent was applied by a Dr. Graham, in 1837. and which possessed the essential features of the principle in dispute. Graham, through lack of means, or for some other reason, had failed to perfect his papers up to the time of his death, and, as the invention was one of obvious importance, a bill was passed through Congress for the reopening of the case, and the patent was issued to the Graham heirs in 1878. Soon after the issue of the Graham patent, several extinguisher firms, viz, Charles T. Holloway, of Baltimore; W. K. Platt, of Philadelphia; S.F. Hayward of New York; the Protection Fire Annihilator Co., of New York; the Babcock Manufacturing Co., of Chicago, and the New England Fire Extinguisher Co., of Northampton, Mass., were licensed to manufacture under the patent, by Archibald Graham, as administrator of the estate of his father, who bound himself in these licenses to issue no other licenses except with the approval of all those who were included in the combination. This arrangement left several enterprising manufacturers out in the cold, and one of these, in investigating the status of extinguisher patents at Washington, discovered an assignment of a quarter interest of the Graham patent to a Mr. Burton, who, at the time of Graham's second application for a patent, had assisted him with $500. This assignment had long been forgotten--Burton having died, and his heirs knowing nothing of its existence. The widow of Burton was hunted up, an assignment was secured for $30,000, and a consolidated fire extinguisher company was formed, which became the owner of the one quarter interest in the patent. This combination, known as the "Fire Extinguisher Manufacturing Co.," included the Protective Annihilator Co., of New York; the Northampton Fire Extinguisher Co, of Northampton, Mass.; and the North American Fire Annihilator Co., of Philadelphia. The combination bought out the Babcock Co., who had already acquired the patents of the Champion Co., all the patents of the Conellies, of Pittsburg, and of the Great American Co., of Louisville, as well as the licenses of S. F. Hayward and W. K. Platt. This covers all the extinguisher patents in existence, except those of Charles T. Holloway, of Baltimore.

The advantages of the chemical engine are well summed up in the following statement:

The superiority of a chemical engine consists--

1st. In its simplicity. It dispenses with complex machinery, experienced engineers, reservoirs, and steam. Carbonic acid gas is both the working and extinguishing agent.

2d. In promptness. It is always ready. No steam to be raised, no fire to be kindled, no hose to be laid, and no large company to be mustered. The chemicals are kept in place, and the gas generated the instant wanted. In half the cases the time thus saved is a building saved. Five minutes at the right time are worth five hours a little later.

3d. In efficiency. Mere water inadequately applied feeds the fire, but carbonic acid gas never. Bulk for bulk, it is forty times as effective as water, the seventy gallons of the two smallest cylinders being equal to twenty-eight hundred gallons of water. Besides, it uses the only agent that will extinguish burning tar, oil, and other combustible fluids and vapors. One cylinder can be recharged while the other is working, thus keeping up a continuous stream.

4th. In convenience. Five or six men can draw it and manage it. Its small dimensions require but small area, either for work or storage. One hundred feet or more of its light, pliant hose can be carried on a man's arm up any number of stairs inside a building, or, if fire forbids, up a ladder outside.

5th. In saving from destruction by water what the fire has spared. It smothers, but does not deluge; the modicum of water used to give momentum to the gas is soon evaporated by the heat, doing little or no damage to what is below. This feature of the engine is of incalculable worth to housekeepers, merchants, and insurance companies.

6th. Economy. It costs only about half as much as a first class hand engine, and about one-fourth as much as a steam engine, with their necessary appendages, and the chemicals for each charge cost less than two dollars.