142 



THE INDIA RUBBER WORLD 



[December 1, 1918. 



this form presents. It would seem that tlie greater the area of 

 a rubber sample in relation to the weight, the greater is the sensi- 

 tiveness, as regards water-content, to changes in the humidity 

 of the surrounding atmosphere. 



The author's chief conclusions are given as follows: The 

 percentage of moisture in raw rubber in the form of sheet or 

 crepe varies considerably with the degree of humidity of the 

 surrounding atmosphere. In rubber-producing climates it shows 

 a diurnal variation. Sheet rubber tends to retain a higher per- 

 centage of moisture than crepe. The moisture-retaining ca- 

 pacity of raw rubber is closely associated with the presence of 

 serum solids. The latter arc very hygroscopic. 



CHEMICAL PATENTS. 

 THE UNITED STATES. 



EL.VSTIC M.ASS.— An elastic mass and its .inanufacture. 

 A vulcanized composition consisting of linseed oil which has 

 been oxidized at a temperature of 200-250 degrees C, aluminum 

 stearate, a mineral hydrocarbon of high melting point, an inert 

 filler, and sulphur. (Eduard Salomon Ali Cohen, The Hague, 

 Netherlands. United States Patent No. 1,280,129.) 



VuLC.^xiziXG Process .^ND Compou.n-d.— Process of vulcanizing 

 rubber-like material which comprises heating, under vulcanizing 

 conditions, a mixture comprising such rubber-like material, a sul- 

 phur material and amino menthyl isopropyl benzene. (Chester E. 

 Andrews, assignor to The Walker Chemical Company, both of 

 Pittsburgh, Pennsylvania. United States Patent No. 1,280,940.) 



THE UNITED KINGDOM. 



Substitutes for Ebonite .\nd Product.— Ebonite substitute 

 is derived from waste or new rubber dissolved in a vulcanizable 

 oil such as rape seed oil, with which has been mixed by heat 

 paraffin wax, stearin, or similar substances, and also resinous 

 material. To this mixture is added finely divided filling material 

 sulphur and other vulcanizing material. The plastic mass is 

 pressed or molded and vulcanized by steam. (Naamlooze "^V 

 nootschap Nederlandsche-Maatschappi tot Exploitatie Van ( ' 

 timiet Fabricken, 200, Van Beuningen-straat, Amsterdam, 

 signees of S. van Raap, 102, Weesperzijde, Amsterdam. Brit^;. 

 Patent No. 118,270.) 



Vulcanizing India Rubber.— The invention consists in heating 

 the rubber, etc., previously mixed with a vulcanizing agent, and 

 discontinuing the supply of heat when the rubber has expanded 

 to an extent indicative of the degree of vulcanization derived. 

 (W. J. Mellersh-Jackson, 28 Southampton Buildings, London. 

 [Morgan & Wright, Detroit, Michigan, U. S. A.] British Pat- 

 ent No. 118,305.) 



THE DOMINION OF CANADA. 



Rubber Vui-camzing Process.— .\ method of accelerating a 

 vulcanizing process which consists in adding to the rubber mix- 

 ture an accelerator comprising caustic alkali dissolved in glycerol 

 or glycol. (Douglas Frank Twiss, Sutton Coldfield, Warwick, 

 assignor to The Dunlop Rubber Company, Westminster, London, 

 both in England. Canadian Patent No. 185,317.) 



THE FRENCH REPUBLIC. 



Rubber Substitute and Process.— A composition consisting of 

 fish oil or fish scrap relatively rich in fixed oil and a reducing 

 agent, probably sulphur, by which under suitable treatment a 

 commercial product results. (The Western Rubber Co., Tacoma, 

 Wash.. U. S. A., French patent No. 487,989.) 



CALCULATION OF PRESSURE OF SOLID TIRES ON WHEEL 

 RIMS. 

 E. Garabiol in "Le Caoutchouc et la Gutta-Percha," October 15, 

 1918, gives the derivation of a mathematical formula for calculat- 

 ing the compression required to secure the non-slip attachment 

 of steel-rim solid tires to wheels under varying conditions of load 

 and speed, giving also the details of calculation in an example. 



LABORATORY APPARATUS. 



A POWERFUL GAS BURNER. 



A VERY effective design of gas burner is the " Hughes- Amlasp" 

 shown in the illustration. It is intended for general laboratory 



use, producing a flame of highest tem- 



pcrature without the use of blast. It burns 

 either natural or artificial gas, and has means 

 for air and gas regulation. By a special per- 

 foration system on the chimney, the gas is 

 evenly distributed and mixed, giving an 

 extremely hot flame, making this burner the 

 closest approach to the blast burner. The 

 temperature of the flame is uniform through- 

 out ; diameter of the flame, nine-sixteenths 

 of an inch.— (American Laboratory Special- 

 ists, Pittsburgh, Pennsylvania. 



Hughes-Amlasp 

 Gas Burner. 



RESILIOMETER, 

 The recently invented instrument known as the resiliometer is 

 being adopted in rubber works laboratories for measuring the 

 resiliency of cured rubber. The resiliometer was originally de- 

 vised to measure the thickness, hardness and resiliency of me- 

 chanical felts for gaskets, 

 washers and piano hammers. 

 It is essentially a combination 

 of a dial type micrometer with 

 a presser foot and platform 

 upon which the material to be 

 tested is placed and a reaction 

 device for determining the 

 compressibility and resilience 

 of the inaterial. 



To determine hardness, pres- 

 sure is exerted on the material 

 under the presser foot by 

 means of the weight attached 

 to the quadrant which sinks the 

 presser foot into the material. 

 The dial reading of thickness 

 after compression, expressed 

 in percentage of the reading 

 of the original thickness, gives 

 the degree of hardness. As 

 The Widney Resiliometer. ^jje weight is removed after 

 the hardness reading has been taken, the pressure of the weight 

 is entirely released from the presses foot and another reading 

 taken, thus giving the immediate resiliency of the material. (The 

 Widney Company, 320 South Jefiferson street, Chicago, Illinois.) 



RHOTANIUM WARE. 



Rhotanium is stated to be the only and original gold-palladium 

 alloy. It is made in two grades for chemical purposes. Rhota- 

 nium "A" in its resistance to alkalies is superior to platinum, and 

 its loss by volatilization at high temperature is also less than 

 for platinum, with melting point at 1,253 degrees C. Rhotanium 

 "C" has a melting point of 1,425 degrees C. Rhotanium ware 

 for laboratory uses is made in all the forms for which platinum 

 has ordinarily been used, with equal satisfaction in service and 

 at much lower prices. (Palo Co., New York City.) 



ViscosiMETER.— A torsion viscosimeter consisting of a torsion 

 element, means for indicating angular defection and an electric 

 heating coil for controlling the temperature of the substance 

 under test. (Ross F. MacMichel, Auburn, Washington. United 

 States Patent No. 1,281,042.) 



Replete with information for rubber manufacturers — Mr. 

 Pearson's "Crude Rubber and Compounding Ingredients." 



