May 1, 1920.] 



THE INDIA RUBBER WORLD 



483 



The trouble of course lies in the fact that the pound and the 

 kilogram bear an unsatisfactory relation to each other. The 

 Bureau of Standards gives this relation as : 



1 pound = .4535924277 kilogram; the present writer has used: 



1 pound = .4536 kilogram. 



Spreader Goods: When fabric is to be covered or "spread" 

 with rubber the calender man is instructed to spread a certain 

 weight of rubber per yard of fabric, this depending on the width 

 of the goods. For every pound per yard he will now spread 496 

 grams per meter of length, because : 



1 pound = .4536 kilogram and 1 yard = 1.0936 meters, and 

 1.0936 X .4536 = .4960569 kilogram, or 496 grams. 



Vulcanizing: The vulcanizing of rubber is done with steam 

 at pressures varying from 40 to 75 pounds per square inch, and 

 so the gages read. In the metric system the steam pressures are 

 expressed in kilograms per square centimeter. Inasmuch as: 



1 pound per square inch = 0.07031 = kilogram per square centi- 

 meter, equivalent readings on the gage now in use and the metric 

 gage compare as follows : 



Present (English) Gage. Metric Gage. 



Pounds Kilograms 



40 2.8124 



45 3.1635 



50 3.5155 



55 3.8670 



60 4.2186 



As metric gages will be marked to even kilograms and prob- 

 ably to lOths of kilograms, a latitude is left to the workman in 

 guessing the pressure he has worked to heretofore. 

 When the metric The pressure in pounds 



gage reads kilograms : per square inch would be : 



3 42.6685 

 3.5 49.7799 



4 54.8913 

 4.5 64.0027 



Those familiar with vulcanizing will readily agree that abso- 

 lutely no guessing is permissible in this operation. Therefore 

 special gages would be required, which, while reading to metric 

 figures, are calibrated to actual English pressures. Similar ob- 

 servations hold good for the testing departments and need not be 

 enlarged upon. Of course a new set of gages, scales and meas- 

 uring tools would have to be installed. 



The superintendent will have his troubles in educating his men, 

 but with patience it may be accomplished, provided he himself 

 has first become proficient. His real diflSculties will come when 

 he has to use compound figures, such as pressures in kilograms 

 per square centimeter; when fabric specifications are changed, 

 giving new widths to be covered by rubber to the same thickness 

 as on the English width fabrics, etc., etc. 



Crude Rubber : While the factory manager and the men in 

 the shop are wrestling with their problems the purchasing agent 

 in his ofTice will be confronted with his own difficulties. Crude 

 rubber is bought by the long ton, 2,240 pounds, and the prices are 

 given in cents per pound. Supposing he needs 50 tons and the 

 price is 47 cents: 1 long ton = 1.016 metric tons, therefore 50 

 tons = 50.8 metric tons, 1 kilogram = 2.2046 pounds and 2.2046 

 X 47 = $1,036 per kilogram. 



The crude rubber importer, dealer and broker are equally 

 affected ; their contracts are changed to metric figures and so are 

 prices, bills of lading, manifests and the whole system of book- 

 keeping. 



Compounding Materials : This holds good for all compound- 

 ing ingredients, sundry supplies, solvents and oils. These are 

 received in bulk, some in barrels, kegs and some in steel drums. 

 And all these varied containers will be known according to 

 metric figures, the goods themselves billed and paid for in like 

 manner. 



Fabrics : Supposing the purchasing agent in need of fabrics 

 looks up quotations on carriage cloth, duck, sheetings, and tire 

 fabrics. They will appear unfamiliar to him in their metric 



designations. The following calculations are made to show the 

 work involved in changing these simple looking quotations from 

 the English to their metric equivalents. 



(A) Carriage cloth duck: 



38-inch 2.00-yard enameling duck yard $0.46 



This quotation interpreted into every-day language means that 

 the cloth is 38 inches wide and that a piece 2 yards long weighs 

 1 pound, and the price per yard of length is 46 cents. 

 To convert this into metric figures : 



38 inches = 38 X 25.4 — 964.2 millimeters. 

 To find the length of cloth weighing 1 kilogrram : 



1 kilogram = 2.2046 pounds and 2 yards of cloth weigh 



1 pound, 

 then 2.2046 X 2 — 4.4092 yards in 1 kilogram. 

 Since 1 yard = 914.4 millimeters and 1 meter = 1.0936- 



yards, 

 4.4092 yards — 4.4092 X 914.4 = 4.032 meters ^ 4 meters. 

 32 millimeters. 

 If one yard costs 46 cents, then 



1 meter costs 1.0936 X 46 = 50.3 cents. 

 The quotation now will read: 



964-niillimeter, 4.032-meter enameling duck.wif/tr $0.50.3 



(B) Sheetings, 40-inch: 



48 X-48, 2.35-yard yard $0.36 



The quotation tells us that this fabric has 48 warp threads and 48 

 filler threads per inch. The fabric is 40 inches wide, a piece 

 2.35 yards long weighs I pound, and the price per yard of length 

 is 36 cents. 



To write this quotation in metric figures, centimeters will be 

 used instead of inches, meters instead of yards and kilograms 

 instead of pounds. 



1 inch = 25.4 millimeters. ( 1 centimeter = 10 millimeters.) 

 40 inches = 40 X 25.4 = 1016 millimeters = 1 meter 

 16 millimeters. 

 To find the number of threads per centimeter : 



25.4 : 10 as 48 : x, and x = 18.9 threads per centimeter. 

 To find the length of sheeting weighing 1 kilogram : 



1 kilogram = 2.2046 pounds and 2.35 yards of sheeting 



weigh 1 pound, 

 then 2.2046 X 2.35 = 5.1807 yards in 1 kilogram. 

 Since 1 yard = 914.4 millimeters and 1 meter = 1.0936 



yards, 

 5.1807 yards = 5.1807 X 914.4 = 4 meters 737 millimeters. 

 Therefore, a piece of sheeting 4 meters 737 centimeters 



long weighs 1 kilogram. 

 If 1 yard costs 36 cents, then: 



1 meter cost = 1.0936 X 36 = 39.25 = 39' i cents. 

 The quotation now will read : 



Sheetings, 1 meter 16 millimeters: 



18.9 X 18.9, 4 meters 737 millimeters meter $0.39J4 



(C) Tire building fabrics: 



17^ ounce, Sakellarides, combed pound $2.90 



This means that 1 square yard of this fabric weighs 1754 ounces 

 and that it is sold by the pound. 

 To convert this into metric figures : 



1 square yard = 0.836 square meter and 1 square meter 

 = 1.196 square yards. 



1 pound = 16 ounces = 0.4536 kilogram or 453.6 grams, 



therefore 1 ounce = 28.35 grams. 



17'/:i ounces = 480 grams = weight of 1 square yard. 



Therefore 1 square meter weighs : 



1.196 X 489 = 584.84 grams, say 585 grams. 



If 1 pound costs $2.90. then 



1 kilogram costs = 2.90 X 2.2046 = $6.39>i 

 The quotation now reads: 



Tire building fabrics : 



585 grams, Sakellarides, combed kilogram $6.39 



