110 



THE INDIA RUBBER WORLD 



[January i, 1907. 



engineer at work on the pump, and he said : " Knowlton, I 

 think that about half of those valves will do all right, but to 

 put them away down in the bottom I would rather have them 

 softer. Will you change them for us ? " I said, "Yes." It 

 was rather a hard thing to do, to take all that stuff back, but 

 to accommodate him I did it. I sent him the valves made of 

 rubber softer and better than the first ones, and, as an actual 

 fact, the total bill was $35 less. That was six years ago, and 

 last year, at one of the meetings of our Club, I was talking 

 with some gentlemen whom I had not met before, who was 

 telling about taking a big pump to pieces in the station, ar.d 

 said : " I took out the greatest set of valves I have ever seen ; 

 to my knowledge they had been there six years ; all I had to 

 do was to grind them off and put them back again. " I had 

 the satisfaction of telling him that I had made them. In 

 this case the best was cheapest, both in first cost and dura- 

 bility. 



GETTING AT THE COST OF GOOD.S. 



[In reply to a question : "Is the rubber packed so as to 

 make it heavy ? "1. It is not the rubber. What brings up 

 the cost is the method of figuring up the whole thing com- 

 plete at a certain average price per pound. The greatest op 

 portunity for mineral compound, and where you are liable to 

 get most of the heaviest minerals, is when medium goods are 

 ordered— medium in vulcanizing. There is not much oppor- 

 tunity in hard or soft rubber — it is not so much the rubber as 

 the minerals required to make it do the work. No one likes 

 to use a hard valve if it is possible to avoid it ; the softer it 

 is the better, and the less noise it makes. Most men would 

 rather have a valve a little soft than a real hard valve ; and 

 in order to accomplish that, and make it stand the pressure 

 and the temperature and the weight of the water it has to 

 lift, you must use some soft materials, and while the surface 

 of the valve, and perhaps the compound throughout, maybe 

 of medium softness, it will be heavy, because one must have 

 zinc or lead or something of that kind to make it do the 

 work. 



[Query : " I don't see why, with lead at 4 or 5 cents a 

 pound, and rubber$i.3S a pound. It brings up the cost."]. 

 Of course, the rubber is the most important element in the 

 cost, and the labor is as much or more in a heavy compound 

 as in a light one. These necessary minerals lower the cost 

 per pound, but increase the weight of the product so that the 

 valve, or any solid article, might cost as much or more than 

 if made of a lighter compound containing a larger quantity 

 of fine rubber and costing more per pound. 

 TESTING RUBBER GOODS. 



There (showing a sample) is an old time piece of rubber, 

 made in i860. - - - It is just as it was sent to me some years 

 ago by the man who gave me its history. 



[Quer}' : " What causes the deterioration of rubber goods 

 — such as you have in stock, before selling them ?"]. They 

 would improve with age, for a j"ear or two. 



[Querj' : "I have understood that rubber with impurities 

 in it loses its life with age. What causes this ? "] . The com- 

 pound put with it. It would not be impurities in the natural 

 rubber. 



[Query: "Is the process of determining the quality of 

 rubber an exact one?"]. I don't think so. Different chem- 

 ists will take the same piece of rubber goods and the results 

 obtained will be different. It is mj' opinion that they cannot 

 tell the exact quality of rubber, they do not understand it 



yet. - - - The methods of any one chemist, followed consis- 

 tently, would give comparative results, though they might 

 not compare exactly with the results of another chemist. 

 Most of the modern mills have a laboratory, and a very ex- 

 tensive one, and nothing is done b}' guesswork. 



[Query : " Can you give an ofthand test of rubber? Say 

 you have several compounds : would the weight of different 

 samples of equal bulk have anything to do with deteiminirg 

 the amount of rubber in each ?"]. It certainly would. The 

 best quality is lighter in weight. On my reccnimendation 

 the United States government is purchasing sheet packing 

 by the square yard instead of by the pound, getting a 

 better quality for about the same cost. - - - 



The tensile strength test is a good one. Take a piece of 

 rubber, say -^\ inch thick, — if it is a pure gum, not a high 

 pressure steam packing, but a cold water or open air piece of 

 compounded rubber. Take a piece ;, inch wide, and if it 

 contains 45 per cent, or more of good, first quality lubler, 

 it will stretch to seven times its length without breaking, 

 and require a tensile strength of 16 pounds to pull it three 

 times its length, and will return to nearly its original meas- 

 urement within three or four minutes. - - - 



I will tell you how you can recognize fine Para or Bolivian 

 rubber. There is nothing in the world like it. The odor of 

 the Indians' smoked ham never leaves it ; you cannot get it 

 out. The smell is the way I tell it. 



RUBBER SUBSTITUTES. 



There are no substitutes for rubber. That is, nothing has 

 yet been produced which of itself will take the place of rub- 

 ber. There are adulterations which are valuable as ingridi- 

 ents, and are used in perfecting the manufactured product. 

 While rubber of itself is the toughest thing in the world, it 

 would be of but little use if not compounded with minerals, 

 etc., used to perfect the manufactured product ard incTf ase 

 its durability. 



We are often, in showing perhaps an excellent piece of 

 rubber goods, received with the remark that it is probably- 

 made of old boots and shoes. Let me say that this is one of 

 the results of which we are proud. 



Boots and shoes, contrary perhaps to the general unin- 

 formed opinion, are made of the best of rubber. In fact, 40 

 per cent, of their cost is good rubber, which is so prepared 

 that it is in such a condition even after using as to be read- 

 ily reclaimable and used as an ingredient, supplanting other 

 less desirable matter and making a better product than cer- 

 tain minerals which we were foinierly obliged to employ. 



There is one opportunity still open for the man who can 

 grasp it, which is the devulcanizing of rubber, such as heavy 

 pump valves, hose lining, tires, and all sorts of articles in 

 general use, to return it to nearly its original condition, 

 namel}', as- just before vulcanizing. The man who can ac- 

 complish this need not feel ccmpelltd to woik again, as he 

 would add to the quantity of available rubber a large amount 

 of stock that could be used again for very many different 

 purposes.) 



The newspapers mention that Chester B. White and 

 Douglass Cross, of St. Louis, have returned from Peru and 

 Bolivia, where they spent a year in prospecting for minerals. 

 They^mention having seen important undeveloped rubter 

 resources, and they look forward to the time when much 

 American capital will go into those regions. 



