Jl'LY 



920] 



THE INDIA RUBBER WORLD 



667 



factories where he made numerous warm friends whu appre- 

 ciated his trustworthiness and strong personality. Mr. Monroe 

 was thirty-seven years of age. His widow and four children 

 survive him. 



WAS NOT A CHRONOLOCICAL REFERENCE. 



Our good friend, the learned editor of the "Bulletin de I'Asso- 

 eiation des Planleurs de Caoutchouc," thus comments upon a 

 recent article : 



"The very distinguished director of The India Rub- 

 ber World, Mr. Henry C. Pearson, in telling the history 

 of plantation rubber in the December number of that 

 review writes: 'When the automobile industry entered 

 on its glorious career, the demand for rubber was such 

 that it rose from its normal price of $1.25 to $3.00 a 

 pound. The dividends thus obtained from the rubber 

 estates — 200 and 300 per cent — excited the British cap- 

 italists, then in a less degree the Dutch and the Bel- 

 gians, and the "Rubber Fever" began.' Our estimable 

 confrere rather mixes up dates. In our pamphlet, 'Les 

 interets Beiges dans les Societes de Caoutchouc en 

 Malaisie et au Congo,' published at the end of 1919, we 

 told that the Belgians had become interested in rub- 

 ber plantations as early as 1887 by creating the syndi- 

 cate of Malaysia. All this before the 'Rubber Craze' 

 of which Mr. Pearson speaks." 



We hasten to acknowledge that our friendly critic is right 

 reg;.rding the early appreciation on the part of the Belgians of 

 the value of Hevea planting in the Far East. It was not the 

 intention to seem to contradict this. The point was that the 

 majority of the plantations installed during the rubber craze 

 were financed by the British. To this we believe our amiable 

 confrere will agree. (The Editor.) 



DETERMINATION OF THE SOFTENING OF 

 PLASTIC MATERIALS.' 



IT n.M long been customary tci compare plastic materials by 

 such tests as melting point, twisting point, penetration, etc. 

 These tests are valuable, but are not easily reproduceable and 

 do not give any indication of the various changes taking place un- 

 der heat. It is for this reason that the following method has 

 been adopted. 



The instrument used for carrying out this test was the Widney 

 Resiliometer, illustrated in Fig. 1, which was adapted so that 

 with a presser foot, C, of ^s-inch diameter, the weight, I, gave 

 a pressure of 200 pounds per square inch. The metal base, D, 

 was replaced by ebonite, in order that loss of heat through con- 

 duction should be as little as possible. The large dial. A, is 

 graduated in 100 divisions, each 1/1000-inch, so that one revolu- 

 tion of the larger pointer or hand is equivalent to an elevation of 

 1/10-inch travel by the presser foot. When the material is more 

 than 1/10-inch thick the hand will revolve more than once around 

 the dial, the number of revolutions being indicated on the small 

 dial B. 



The operations are as follows : the thickness is first determined 

 by placing the sample between C and D, the normal thickness 

 being read off on the dial. The spring-catch, E, is now released, 

 holding the weight, I, and the quadrant. F, allowed to swing until 

 the pressure is put on the upper end of presser foot, G, at the 

 top of dial. This forces the foot into the material until it reaches 

 the limits of compression as the result of the weight applied. The 

 reading on the dial at that time is taken and compared with the 

 normal or original thickness. For example, a sample having a 

 normal thickness of 100 mils, (one mil. ^ 1/1000-inch) gave a 



'•■The Softening of Plastic Materials Determined by the Widney Resiliom- 

 eter and Expressed Graphically." Bv .Man Speedy. "Journal of the 

 .-Society of Chemical Industry," January 31. 1920. 



reading at 200 pounds per square inch of 25, namely at this pres- 

 sure the material would show a compression of 25 per cent. 



A sample of convenient 

 size for testing is 2.5- 

 inches by 0.5-inch by 

 0.100-inch thick and is 

 easily obtainable by aid 

 of a small mold, the 

 shape of the sample per- 

 mitting several tests to 

 be determined throughout 

 its length. 



The test piece, which 

 should be molded about 

 twelve hours before test- 

 ing, is placed in water at 

 60 degrees F. or lower, 

 depending on the sample, 



and maintained at the re- F^c. 



quired temperature for a a, Dial. B, Revolution Counting Diau 

 few minutes to ensure C, Presser Foot. D, Base. E, Sfiing 

 that the sample is uni- ^"'^"- !:- Q"*"''*''^. G, Upper End of 

 , , , , , , Presser Foot. H, Tkansmission Plcnge«. 



formly heated through- i_ weight. K, Toothed Pivot. 



out. It is then quickly 



taken out, its compression taken and replaced in the bath, the 

 temperature of which is then raised at the rate of about 4 de- 

 grees F. a minute to the next reading, the sample being tested at 

 every 10 degrees F. 



Pressure:?001b.persq. in Degrees Fanrenheit 

 iO 40 50 GO 70 80 90 100 IIP l?0 130 140 150 



Gr.^ph Showi.ng 



When dealing with complex substances which have no definite 

 constant, the value of these curves will be at once apparent. The 

 author has found the curves most instructive and of great as- 

 sistance in controlling running batches of material. 



THE MERCHANTS' ASSOCIATION ELECTS NEW MEMBERS. 



The Merchants' .-Kssociation. Xew York City, on June 21, 1920, 

 elected to membership the following individuals of interest to the 

 rubber and allied trades : Edward C. Beard. 106 Duane street, 

 New York City, assistant treasurer of The Beacon Falls Rubber 

 Shoe Co., Inc., Beacon Falls, Connecticut; Frank Waldo, E. M. 

 and F. Waldo, 11 Broadway. New York City, manufacturers and 

 importers of dry colors for the rubber and allied trades; B. L. 

 .•\twater, 1889 Metropolitan avenue. Brooklyn, New York, vice- 

 president of William Wrigley, Jr., Co., Brooklyn, chewing gum 

 manufacturer. 



Buy W.ar S.wixc-; Stamps — Build for .\.\ieric.\.\ prosperitv 

 and your own success. 



