May io, 1889.] 



SCIENCE. 



363 



tion from what part of the country he comes. For the study of 

 pronunciation the received spelling is very ill adapted, and a pho- 

 netic system is needed if this part of the work is to be conducted 

 in an intelligible manner. In the cases mentioned under I., where 

 the pronunciation is of only secondary importance, such a system 

 is not needed. It is necessary only where the pronunciation is the 

 main thing to be noted, though it will be welcome whenever the 

 pronunciation might be doubtful. A practical, though necessarily 

 imperfect, system of phonetic spelling will be sent to any person 

 who communicates with the secretary. 



The officers of the society are, president, Francis J. Child, Cam- 

 bridge, Mass.; vice-president, James M. Hart, Cincinnati, O. ; 

 secretary, Edward S. Sheldon, 27 Hurlbut Street, Cambridge, 

 Mass. ; treasurer, Charles H. Grandgent, Cambridge, Mass. ; edit- 

 ing committee, the secretary ex ojficio, George L. Kittredge (Cam- 

 bridge, Mass.), Sylvester Primer (Charleston, S.C.) ; executive com- 

 mittee, the officers named above, and Benjamin I. Wheeler (Ithaca, 

 N.Y.), Charles F. Smith (Nashville, Tenn.), Frederic D. Allen 

 (Cambridge, Mass.). 



THE BOWER-BARFF RUSTLESS IRON PROCESSES. 



These processes have for their object the protection of iron and 

 steel from rusting. This result is obtained by the conversion of 

 the surface of the metal into magnetic oxide of iron. The oxide is 

 well known in its natural state as magnetic iron ore, which has 

 withstood without deterioration or change centuries of exposure 

 to the atmosphere and to fresh and salt water. 



The Barff process consists essentially in subjecting to the action 

 of superheated steam the articles which are to be rendered rust- 

 proof. The treatment is carried out in a specially constructed 

 furnace, and is more particularly applicable to wrought iron and 

 highly finished and polished work. 



The Bower process accomplishes the formation of magnetic ox- 

 ide upon iron articles by subjecting them successively to the ac- 

 tions of highly heated air and carbonic-oxide gas derived from coal 

 fires. The hot air converts the metallic surface into red oxide of 

 iron, which is reduced to the black or magnetic oxide by the gas. 



No foreign material, such as paint, alloy, or chemical of any 

 kind, is applied to the metal ; so that the coating is perfectly in- 

 nocuous, and, owing to the simplicity of the process, its cost is less 

 than that of galvanizing. 



Surfaces of iron and steel treated by the Bower-Barft processes 

 present a pleasing blue-gray or blue-black color, and preserve the 

 sharp outline of artistic designs, while, if the articles are polished 

 before treatment, the result of the oxidation is a lustrous, ebony- 

 black finish. 



The Bower-Barff processes have now a record of over four years 

 in the United States, so that it is no longer necessary to refer to 

 European practice for evidences of their value. In furnace con- 

 struction, and other particulars, marked improvements have been 

 made. Furnaces have already been established in the States of 

 Pennsylvania, New Jersey, New York, Connecticut, Massachusetts, 

 and Illinois, and others will shortly be erected. 



The oxide process is applicable to all forms of cast, malleable, 

 and wrought iron and steel, where the surfaces are not subjected 

 to very severe friction, nor injured by subsequent manipulation. It 

 is gradually supplanting the expensive and usually unsatisfactory 

 galvanizing, and for ordinary culinary utensils is taking the place of 

 tinning and enamelling. Where, for the sake of appearance, en- 

 amel is preferred, English manufacturers have adopted the process, 

 because it is found that by first oxidizing the articles the enamel is 

 rendered far more durable. 



The demand by users of cast and wrought iron pipe for plumb- 

 ing, drainage, gas, salt-works, steam-heating, and wherever it is 

 desirable to protect pipes from rusting, is one of the most signifi- 

 cant indications of the recognition of the value of the process. 



The following brief review of the processes, in their leading 

 features and recent developments, may serve to show how readily 

 they can be adapted through a very extended range of iron manu- 

 factures. 



The conversion of the surface of metallic iron into magnetic 

 oxide of iron is carried out in a furnace. The articles to be treated. 



whether large or small, are loaded upon an iron drag, and shoved 

 into a fire-brick chamber, known as the oxidizing-chamber of the 

 furnace. Gas-producers, which constitute a part of the furnace 

 structure, generate carbonic-oxide gas from a thick bed of coal upon 

 the producer-grates. This gas is burned by an admixture of air in 

 a combustion-flue beneath the oxidizing-chamber ; and either the 

 burning gases, or the hot products of combustion, according as the 

 gas and air valves are regulated, enter through ports into the 

 chamber, heating the charge, and then passing through exit ports 

 to the chimney. After the goods have been raised by this means 

 to the desired temperature, which may vary from an incipient red 

 to a cherry heat, depending on the nature of the work, the treat- 

 ment of the charge is begun. If the goods consist ol castings, the 

 Bower process of alternating oxidizing and reducing operations is 

 generally employed. During the period of oxidation, the connec- 

 tion with the gas-producers is almost entirely cut off by a damper ; 

 and air, raised to a high temperature by passing through the hot 

 combustion-flue above mentioned, enters the chamber and oxidizes 

 the iron, converting its surface into the red oxide of iron (FcjOa). 

 After about forty minutes of this treatment, the admission of air to 

 the furnace is stopped, and the producer-gases are allowed to pass 

 for twenty minutes through the chamber without any admixture 

 whatever. The chemical action of these gases upon the ironware 

 results in a change or reduction of the superficial coating of red 

 oxide of iron into the black or magnetic oxide (Fe O4). The op- 

 erations are repeated a number of times, so that the whole treat- 

 ment lasts from ten to twenty hours, according to the thickness of 

 the coating to be produced. At the end of the treatment the 

 charge is withdrawn, and the furnace is then ready for treating 

 another lot of ware. 



The Barff process for wrought iron is carried out in the same 

 furnace designed for the Bower treatment. The articles are 

 charged and heated in the same manner as above ; and, when the 

 proper temperature is reached, highly superheated steam is intro- 

 duced into the oxidizing-chamber, where a slight plenum, not ex- 

 ceeding one to two inches of water-pressure, is maintained for a 

 period of ten to twenty hours. The steam from a half-inch pipe 

 more than suffices for all the requirements. The superheating is 

 easily effected by a continuous coil-pipe superheater, or by a couple 

 of small intermittent superheating chambers, each filled with a 

 loose checker-work of fire-brick, and forming part of the furnace 

 structure. 



The Bower or air process is the more economical one for the 

 treatment of ordii^ry cast iron ; whereas, for wrought and mallea- 

 ble iron, the Barff or steam process has been found more advanta- 

 geous. Where wrought and cast iron work are combined, the 

 Barff process is applicable. The steam treatment of the cast iron 

 in such a case merely necessitates a longer period of exposure in 

 the furnace than would suffice for producing the desired coating by 

 the air process. 



The mechanical finish of the iron, be this either wrought or cast, 

 determines to a large extent the mode of treatment. Rough arti- 

 cles, from which the skin has not been removed, require for the 

 formation of a proper coating in a given time higher heat and more 

 energetic oxidation than goods whose surfaces are more or less 

 finished. A high heat on a finished surface tends to blister and 

 detach the magnetic oxide as it is formed. When articles, there- 

 fore, present some finished surfaces, and others which are rough, a 

 comparatively low heat is used in the oxidizing-chamber, thereby 

 precluding the possibility of injuring the surface; while the treat- 

 ment is continued for a sufficient length of time to insure a thor- 

 ough oxidation of the rough parts, even at the reduced tempera- 

 ture. 



For the steam treatment of highly polished articles, a small 

 muffle furnace is employed. The charge is heated by a flame 

 which plays externally around the muffle. The increased expendi- 

 ture of fuel thus incurre.d in heating the articles is more than com- 

 pensated, ia a furnace of small size, by the ease with which even a 

 slight overheating of any portion of the polished goods is pre- 

 vented. 



The magnetic oxide coating is very hard, but comparatively in- 

 elastic. It withstands the wear due to friction, but is injured by 

 blows of the hammer and rough usage. Wherever from this cause 



