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T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
AN ADVANTAGE FOR THE GAS-ANNEALING FURNACE In these days of scarce and dear sulfuric acid, says Gas Wovld, 66 (1917), 5 2 2 , when endeavors are being made to substitute nitre cake in many processes, it would appear that an additional merit has been found in the gas-annealing furnace. I n a paper before the Birmingham Society of Chemical Industry, Dr. H. W. Brownsdon, giving his experience with nitre cake in the pickling of annealed brass, says that, according to the conditions of annealing, the brass may be clean, practically free from superficial oxides and of a brassy lustre, or it may be dirty, black in color and badly stained through oxidation and contact with injurious furnace gases. Given clean work, nitre cake replaces dilute sulfuric acid quite efficiently, the nitre cake being, of course, applied as a solution. With dirty work, the difference is much more marked and nitre cake solution, even under the most favorable conditions, may fail to pickle the work satisfactorily. I n the latter case, the use of nitre cake in place of sulfuric acid becomes a serious handicap and deterrent to rapid production, especially when manufacture consists of a sequence of mechanical operations between each of which the product has to be annealed, pickled and cleaned. From the point of view of economy in future developments, with ruling prices in England, a t present, of $ 2 0 per ton for sulfuric acid and with nitre cake a t $5 per ton, there is not much to choose but the economy of metal which would result from the more general use of muffles annealing bright and clean would be considerable and, if the use of nitre cake forces us to pay more attention to economical annealing conditions, it will have achieved indirectly some good purpose. The cleanliness and easy regulation of the gas-heated annealing furnace should make themselves felt here.-M.
SYNTHETIC RUBBER FROM CARBIDE The manufacture of acetone with a view to the production of synthetic rubber is of considerable importance in Germany a t present. The importance of this industry, says Chemical Trade Journal, 61 (1917), 2 6 , is indicated by the fact that some of the largest firms in Germany, such as the Konsortium fur Elektrochemische Industrie of Nurnberg, the Elektrotech. Werke of Bitterfeld, the Farbenfab. of Bayer & Co., Griesheim, and others, have been occupied with this problem for some years. There are firms in Germany producing I O to 50 tons of carbide per day in order t o convert the acetylene into acetic acid and acetone, the latter being intended chiefly for the production of synthetic rubber. This new industry ,should be of special interest to Switzerland, since the necessary carbide will in the future be available in large quantities in that country. After the war, the export of carbide will be considerably reduced and this product will, therefore, become much cheaper. On the other hand, the price of rubber will remain high for several years. In order to protect this young industry, it is suggested that Switzerland should impose a duty on imported rubber, since the countries which export crude rubber will doubtless put an export tax thereon.--M. ~
ESTIMATION OF BENZOL IN GAS Dr. Ott, of the Zurich gasworks' laboratory, has been trying Neubeck's method of freezing out benzol from gas with solid carbonic oxide and has found it to work very well. I t gives a condensate unmixed with oily matter but, as it has a specific gravity of only 0 . 8 5 2 a t 1 7 " C., it probably contains lighter components dissolved out of the gas. The method enables a uniform temperature, -79' C., to be repeated and maintained in successive experiments-AI.
1701. 9 , No.
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BROWN PAPER FOR LEATHER Under the provisions of the long-delayed Footwear Regulation Act, says the Melbourne Age, the people of Australia will be entitled the protection against the audacious swindling which has led to the substitution of brown paper for leather in certain classes of boots. The Law provides that they may ascertain whether the boots offered them by the mender are made of genuine leather or of mere shoddy. The sole of a boot or shoe must be stamped with particulars of the material of which it is made. The Act, unfortunately, is not t o operate a t once. Parliament decided to allow the trade six months within which t o get rid of old stocks of shoddy material before the coming into force of the measure. The Chief Secretary said recently that the act would operate from July 1st and there would be no postponement.-&I. PROJECTION OF BOMBS When a bomb is dropped from a moving aeroplane the point a t which it strikes the earth depends primarily on its altitude above and speed with respect to the earth's surface, and to a smaller extent on the speed of the wind and the mass and surface of the bomb. In order to allow the aviator to drop his bomb on a given object, the most recent German aeroplanes are provided with an instrument made by Goerz, which consists of a telescope kept vertical by means of a bubble of air in the eyepiece. By means of a movable prism below the objective, the observer can adjust his instrument, so that he sees objects through it a t a given angle ahead or in the rear. The instrument is generally used when the aeroplane is moving against the wind. From the aneroid reading of the height of the aeroplane and the time taken to get vertically over an object seen previously 2 2 . s o ahead, the speed of the aeroplane is known. The speed of the engine gives the speed of the aeroplane through the air so that the speed of the air is known and for a given bomb the angle a t which the line of sight of the instrument must be ahead in order that a bomb released when the object is seen in the telescope may strike that object is also known. Variations of direction of flight of the aeroplane and of strength and direction of the wind cause errors which are to some extent eliminated by further devices which are described in La LVaturefor June 19.-M. BRITISH BOARD OF TRADE During the month of July inquiries have been made by firms in the United Kingdom and abroad concerning the following articles. Firms able to give information regarding sources of supply of these articles are requested to communicate with the Director of the Commercial Intelligence Branch, Board of Trade, 7 3 Basinghall St., London, E. C. Bangles and bracelets, imitation silver Beads, imitation Brass-wire brushes for goldsmiths Carbon electrodes Circular saws, 3 in. diameter and 32-33 W. G. Confetti Citrate of iron and ammonium (500 kil. for export) Clock escapements for ships' lever movements Diamond dies for wire drawing Drawing pins Enamelled kettles Fine silver chain, machine made Glove stretchers. boxwood Gramophone motors Gilt guard chains Granular-oak charcoal MACHINERY A N D PLANT Boilers designed for using peat as fuel Gas-generators designed for peat Machinery for excavating and handling peat Disintegrating machinery for treating leather waste
Machinery for making fez Machinery for making glass beads Machinery for plaiting cane Machinery for making basket chairs, etc. Maize oil S i t r i t e of soda Pendants, for African trade Persulfate of soda Piercing saws for metal Pony hair. fine brown, Japanese or other, for camel hair Pencils for medical trade Rubber tabs for sock suspenders Stamped brass coats o f a r m s , size about 8'/2 in. X 6'/r in. Silver. bags. ladies Steel and brass pins. fine Schools chalks Tin. brass and copper linings and angle plates for ammunition boxes Thimbles Wood tar Yellow ochres, suitable for grinding Zinc sheets, 14 gauge, for war work
-M.
