August.]. 1919.; 



THE INDIA RUBBER WORLD 



613 



consists of a white lacquered iron frame, on top of which are 

 white lacquered planks. To each table belong a mat, a head- 

 cushion and a blanket. Mosquito-proof wards are provided for 

 malaria patients and special wards are set apart for the treat- 

 ment of anemia and beri-beri. Filtered water is furnished from 

 a near-by well under pressure. Food in the hospital is prepared 

 for the Chinamen by Chinese cooks and for the Mohamedans 

 by Javanese. The staff includes both European and native sur- 

 geons and chemists. 



THE WORLD'S LARGEST RUBBER ESTATE. 



.^t the present time the company owns property in Sumatra 

 aggregating about 90,000 acres, of which 45,000 acres, or approxi- 

 mately 70 square miles, are fully planted. This constitutes the 

 largest group of rubber estates in the world. Perhaps the New 

 Yorker will obtain a clearer conception of its size by the statement 

 that the planting acreage is over three times the size of Man- 

 hattan Island. If its more than five million trees were planted 

 in a row nineteen feet apart — the distance between each tree 

 on the plantation— they would extend over 19,000 miles, or more 

 than three-quarters the distance around the world. 

 PRODUCTION STEADILY INCREASING. 



During 1914 the first shipment of rubber from the company's 

 own plantations was received in .America, and while the quantity 



Hekr the Rubber Is Being Blocked and Baled for Shipment 

 TO THE Home Factorie.s. 



that year and also in 1915 was relatively small as compared with 

 the requirements of the United States Rubber Co., the amount 

 received in the ensuing period has steadily increased. About 

 eighty-five per cent of the trees on the plantations are now in 

 bearing, and with many young trees arriving at the bearing age 

 and all the trees increasing in yield with their increasing girth, 

 the plantations will produce more and more rubber each year. 

 A VALUABLE ASSET. 

 Due to the efficiency of the Dutch planting organizations and 

 the able staff of the company, the yearly development program 

 has been carried out practically without interruption. Exten- 

 sions to the planted area are contemplated at an early date, and 

 the outlook for the future is regarded as promising. Already 

 the plantations are proving to be one of the most valuable assets 

 of the United States Rubber Co. 



RUBBER CEMENTS'. 

 ACID PROOF. 



RUBBER cements may have varied composition. If equal 

 parts of fresh unvulcanized rubber and oil are used the 

 mass is so stiff that it could probably be used alone. If as much 

 as four parts of linseed are used considerable filler can be incor- 



porated and make a workable putty. Equal weights of rubber 

 and boiled oil are taken ; the rubber is first dissolved in carbon 

 disulphide in the proportion of 4 cc. of carbon disulphide to 1 gr. 

 of finely cut rubber. Boiled linseed oil is then mixed in, and if 

 the oil is warm the mixing is facilitated. The solvent is generally 

 not removed by evaporation until the paste is applied. 



Another formula differs in having four times as much boiled 

 linseed oil and then fire clay or other filler, such as silex, is used. 



Parts of Weight. ' 



Crude, finely cut rubber 1 



Linseed oil, boiled 4 



Fire clay 6 



MARINE GLUE. 

 Standard preparation of this class of cements, which are applied 

 lo crevices, hot, and get firm but not brittle when cold, is com- 

 posed as follows : 



Parts of Weight. 



Crude rubber 1 



-Shellac 2 



Pitch ,. 3 



The rubber is first dissolved in carbon disulphide or turpentine 

 before mixing with the heated (not superheated) mixture of the 

 other two. The advent of blown patroleum residuums has made 

 it pos.sible to make up hard but flexible compounds without rub- 

 ber. Grahamite is a good base to which fluxes, such as these 

 just mentioned or soft asphalts, are added. 



GASKET COMPOSITIONS. 



In the laboratory one can generally make out for low tem- 

 peratures and pressures by saturating heavy "kraft" wrapping 

 paper with soft pilch, such as wood pitch for steam or with 

 gelatine and glue (hectograph) composition for oils. For high 

 pressures, slots filled with lead rings and a V-shaped rim to tl^e 

 lid are most satisfactory. • 



MACHINISTS' CEMENTS. ; 



.-K few words might be said here with reference to machinists' 

 cements. These are the well-known red and white leads. The rdd 

 lead is often diluted with an equal bulk of silica or other inert ■ 

 substance so as to make it less powdery on drying. The belt .- 

 way to accomplish this is to add rubber or gutta percha to tWe 

 oil as follows : • 



Parts of Weight. = 



Linseed oil 6 ' 



Rubber or gutta-percha 1 [ 



The rubber or gutta percha is dissolved in sufficient carbcjrt 

 disulphide to give it the consistency of molasses, mixed with tl|e 

 oil, and left exposed to the air for about 24 hours. The red lead 

 is then mixed to a putty. Oxide of iron makes less brittle cement* 

 than red lead. I 



LEATHER CEMENTS. ' 



The following formulas are given in the "Papier Zeitung": (1") 

 equal parts of good hide-glue and American isinglass, softenejd 

 in water for 10 hours and then boiled with pure tannin until the 

 whole mass is sticky. The surface of the joint should be rough- 

 ened and the cement applied hot. (2) One kilo of finely shredded 

 gutta percha digested over a water-bath with 10 kilos of benzol, 

 until dissolved, and 12 kilos of linseed-oil varnish stirred in. (3,) 

 Seven and one-half kilos of finely shredded India rubber are 

 completely dissolved in 10 kilos of carbon disulphide by treating 

 while hot, 1 kilo of shellac and 1 kilo of turpentine are added, 

 and the hot solution heated until the two latter ingredients are 

 also dissolved. Precautions against fire and vapors should fee 

 observed. (4) Another one noticed in the "Journal of the So- 

 ciety of Chemical Industry": gutta percha, 8 ounces: pitch, 1 

 ounce : shellac, 1 ounce ; olive oil, 1 ounce. These are melted 

 together. '■ 



SOUVENIRS. j 



The Pioneer Asphalt Co., Lawrenceville, Illinois, is presenting 



its customers with a novel "Redipoint" pencil. 



A useful desk souvenir from the Rolle Rubber Co., of Neyir 



York and Chicago, is a permanent stone blotter. 



