TAYLOR'S RULES 17 



per square inch of section. This corresponds to an effective 

 pulling power of 30 Ib. per inch of width. 



3. If double belts are tightened while at rest to 71 Ib. 

 per inch of width and subjected to an additional working 

 load of 65 Ib. per inch of width, the tension in 2\ months 

 will fall to 33 Ib. per inch of width while at rest or 106 Ib. 

 per square inch of cross-sectional area. The average tension 

 during this period will be 46 Ib. per inch of width and the 

 average total load in Ib. per inch of width, or 358 Ib. per 

 square inch of section. When double belts are first tightened 

 to 71 Ib. per inch of width and then subjected to an additional 

 working load of 26 Ib. per inch of width, their tension will 

 fall in twenty-two months to 21 Ib. per inch of width or 68 Ib. 

 per square inch of section. The average tension during this 

 period will be 28 Ib. per inch of width or 90 Ib. per square 

 inch of cross-section, and the average total load will be 54 

 Ib. per inch of width and 174 Ib. per square inch of section. 



4. The total stretch of leather belting will exceed 6 per 

 cent of the original length. The stretch during the first 

 six months of the life of a belt is 36 per cent of the entire 

 stretch if the belt is a double belt working under a total load 

 of in Ib. per inch of width and giving an effective pull of 

 65 Ib. per inch of width. If, however, the belts are working 

 according to the more economical rule, under a total load of 

 54 Ib. per inch of width, giving an effective pull of 26 Ib., 

 the stretch during the first six months will be but 15 per 

 cent of the entire stretch. A double belt will stretch 0.47 

 per cent of its length before requiring to be tightened when 

 subjected, according to the ordinary rules, to a total load 

 of in Ib. per inch of width. A double belt with a total load 

 of 54 Ib. per inch of width and an effective pull of 26 Ib. 

 stretches 0.81 per cent before requiring re tightening. 



5. Belt clamps having spring balances between the two 

 pair of clamps should be used for weighing the tension of 

 the belt accurately, each time it is tightened. When it is 



