NOTES A N D CORRESPONDENCE. Time in minutes.
Temperature in degrees centigrade.
10 12 14 16 18 20 22 24 26 28 30
368.0 314.0 271 .O 238.0 206 . O 180.0 158.0 140.0 125 .o 112 .o 100.0
741
In view of the fact that the writer has received a great many inquiries as to the method of making the electric furnace referred to in the article entitled “Economy in the Gse of Oxygen, Etc.,” he believes that a note describing the Same may be of interest to others.
project far enough for a connection and wind the strip of platinum tightly around the tube, leaving about 1/4” or more between turns and fasten with the clamp at the other end, allowing i t to project in a similar manner for connection with the current. The length of the tube wound with resistance should be about 9” and not more than IO”. Cover this with a plaster about 1/8” to 1/4” thick made of broken up pipe covering mixed with water and enough fire clay to act as a binder, putting i t on in much the same way as frosting is put on a cake, thus enclosing the resistance in an infusible casing which proves very efficient in preventing a short circuit. Next cut off a piece of magnesia pipe covering ( I 3/4” inside diam.) 9“ long and put i t around the tube, replacing the cloth cover with asbestos and fasten i t on with a fern turns of iron wire. Prepare a stand similar to that in the illustration (scale: 1/2” = 1’) in THIS JOURNALand place on the iron brackets of the stand two pieces of pipe covering, one inside the other, the outside one having an inside diameter of j ” , and the inside one a n outside diameter of 7“. Slip the tube into its position and strap i t down with pieces of leather thong to the two uprights-these should be of such a height above the brackets as to support the
The furnace is strictly “home-made” and gives excellent service. As before brefly explained, i t is a porcelain tube wound with a platinum resistance and jacketed with pipe coverings. A porcelain tube is to be preferred to one of quartz on account of the repeated annealing i t has to undergo in cooling off every night. The condition of the former is improved by such treatment, but the latter assumes a crystalline structure and becomes very brittle. The tube should be about two feet long and one inch in diameter. The resistance is a strip of platinum foil, 8 feet long, 4 mm. wide, and about IO mm. thick, with the last four inches of each end left about IO mni. wide in order to have metal enough to make a good cool connection with the circuit. To make up the furnace, moisten a piece of sheet asbestos 16” long by 1/16“ thick, and wide enough to encircle the tube, and wrap i t once around the tube, having first covered the latter with n little water glass solution. Make a couple of clamps of sheet nickel. These are bands about I / Z ” wide and 1/32” thick clamped together with small bolts and nuts and are intended to hold the two ends of the foil. P u t them on about six inches from each end of the tube and clamp one end of the foil under one of them, letting i t 1 THIS JOURNAL. 1, 375.
tube independently of the outside jacket-then plaster up each end of the jacket with a paste of pulverized pipe covering or of asbestos cement and the furnace, is ready for use Sometimes the heat fuses the inside of the tube a little, but when this is the case, magnesium oxide spread out on the inner surface will soon prevent any further trouble I t is necessary to use a nickel rod or wire to push the boat into the tube, as a n iron rod becomes magnetized and Rill pull the drillings from the boat on being withdrawn l y e are a t present using this furnace on a 2 2 0 volt direct current circuit in series with a lamp back of twelve to fourteen one ampere ( IOO c. p.) lamps. This gives a current of about 1 2 amperes n i t h a drop across the furnace of 30 to 35 volts and a temperature of I I O O O to I Z O O O C. This, of course, can be regulated to almost any degree by changing the number of lamps. I t is possible to attain a temperature of 1 5 0 0 ~C., but i t is not advisable to run it as high as that, both on account of the liability of a burn-out and the loss of platinum by volatilization. I n case a burn-out occurs i t is a simple matter to weld the foil electrically, thus making quick repairs possible. I n fact i t is possible to entirely dismantle and rebuild this furnace in less than a n hour. The cost of the furnace need not exceed $30, and i t
DEMILLECAMPBELL, NATHANIEL GOTT.
EDWARD
EDC4R CHEMICAL LABORATORY,
UNIVERSITY OF MICHIGAN; ANNARBOR.
HOME-MADE ELECTRIC FURNACE.
742
T H E JOC’RNAL OF 1,VDUSTRIAL A N D ENGINEERING CHEMISTRY.
may be made for much less and operated with much less power if a thinner foil is used as a resistance. The dimensions given, however, are preferable for furnaces irk continuous operation. The ideal method of using such a furnace is in conjunction with a motor-generator set, but the following sketch will show the method of wiring above described. WM, HERBERTKEEN. LABORATORY O F THE FILTH STERLING STEELCo , WASHINGTON. D C.
BOOK REVIEWS AND NOTICES.
Oct., 1909
Fertilizers. Artificial Manures: Their Chemical Selection and Scientific Application to Agriculture. By M. GEORGEVILLE, translated and edited by SIR WILLIAMCROOKES. New edition revised by SIR WILLIAMCROOKES,D,Sc., F.R.S., and JOHN PERCIVAL, 31.A. 6 plates. 8\70. pp. xl, 348. Longmans, Green & Co., London and New York. Price, $3.00 net. Chemical Conversion Tables. For use in the analysis of fertilizers, fertilizing materials, iron and its products, etc. By H. B. BATTLE, PH.D., and I\’. J. GASCOYXE, PH.D’, Pocket size, indented reference index. Williams & Wilkins Pub. Co., Baltimore, Md. Price, $2.50.
.\fining and illetallurgy. The Lead and Zinc Pigments. By CLIFFORD DYERHOLLEY, M.S., PH.D., Chief Chemist, Acme White Lead and Color Antimony. By WAXG CHCNG Yu. J. B. Lippincott Co., 340 pp., 8 j figures. Cloth, $3.00 Works. Izmo. xv Philadelphia. 1909. Price, $4.00. net. Kew York: John W l e y & Sons. The Nature of Ore Deposits. Translated and revised by W. The thirty-one chapters of this book contain much that H. WEED. R . BECK. 1909. Hill Publishing Co., Sew is of interest and value. Much of the matter is of a hisYork. $6.00. torical and descriptive nature. The analytical methods Fuel, are in the main adequate. Among the defects of the work On the Rate of Formation of Carbon Monoxide in Gas Proare selection of illustrations of superficial rather than inUniversity of Illinois, Urbana. ducers. By J. K. CLEMENT, trinsic merit (notably the frontispiece), and the addition of 1909. an appendix containing tables which are already in the Das Erdol, Seine Physik, Chernie, Geologie, Technologie, Etc. possession of all chemists in books of more convenient form. By C. EXGLER and H. HOFER. j bande Band 2 . Geologie, Gewinnung und Transport. Mk. 46, geb. jo. The Scientific and Industrial Bulletin of Roure, Bertrand Fils, of Grasse, for April, I909 (Series 2 , No. 9), while appearPaids. ing rather late contains much matter of interest in connecLead and Zinc Pigments. By C. D. HOLLEY. John Wiley tion with essential oils. Among other articles are these: & Sons. Xew York. Price, $3.00 “The Resin Industry of the Landes;” “Contribution to the Industrial Chemistry. Study of Perfume-Yielding Plants ;” “The Suppression of Fraud So Far as Essential Oils Are Concerned;” “Review Chemistry for Engineers and Manufacturers. By B. BLOUXT of Recent Kork on the Perfumes and Essential Oils.” 8vo. and A. G. B ~ o x a a i . Vol. 11. The Chemistry of hlanupp. 160. facturing Processes. 8vo., cloth, Ill., j 1 4 pp. J. B.
+
Lippincott Co., Philadelphia. Price, $4.00. The Mineral Content of Illicois Waters. Bulletin go. 4 Cane Sugar and Its Manufacture. By H. C. PRINSEN GEERIllinois State n’ater Survey. Prepared in Cooperation LIGS. Large Bvo., pp. 3jo. 12s. Norman Rodger, BARwith the State Geological Survey. By EDWARD TOW, J. .4. UDDEN, S. IT.PARR, and GEORGET. PALXER, Altrincham, Manchester. Urbana, 1909. Tables and Diagrams of the Thermal Properties of Saturated S. MARKS,M.X.E., and Supersaturated Steam. By LIOXEL This volume contains an introduction by Edward Bartow; N. D a v ~ s . , PH.D. Large 8vo., pp. 106. and HARVEY Geological Classification of the 1Taters of Illinois, by J . 4. Longmans, Green & Co., London and Sew Uork. $41.00 Cdden ; Classification of Mineral n‘aters, According to net; by mail $1.10. Physical and Chemical Properties, by Edward Bartow; Methods and Interpretations, by Edward Bartow ; Boiler Die Fabrikation der Lacke, Firnisse und des Siegellacks. By ERICHDETTMERS. ( I 16 Band, Bibliothek der gesamten LYaters, by S. W.Parr; Mineral Springs of Illinois, by George Technik.) 8 dbh. Nk. 2.60. 51. Janecke, Hannover. T. Palmer, M.D. Chemisches Auskunftsbuch fiir Fabrikanten, Gewerbetreibende und Landwirke. By HCGO KRAUSE. A. HartleNEW BOOKS. ben, Leipzig und \Vien. hIk. 4.80. --This list was prepared by M r . Paul Escher, 1319 Pearl Street, Alameda, California.
Agricultural Chernzstry. Moisture Content and Shrinkage in Grain. By J. m-. T. DUVEL. pp. 13. (Circular 32, Bureau of Plant Industry.)
SCIENTIFIC AND INDUSTRIAL SOCIETIES. ASSOCIATION O F STATE AND NATIONAL FOOD AND DAIRY DEPARTMENTS.
The thirteenth annual convention of the Association of Agriculture for Southern Schools. By JOHN FREDERICKState and National Food and Dairy Departments was held DUGGAR. Louisiana edition. MacMillan Co., New York. a t the Brown Palace Hotel, Denver, Colo., August 24-27, Ill., 12. $.60x. Cloth, xi. 340 pp. xlii pp., index. 1909. On the opening day, August 24, addresses of wel-
