BELTING TABLES 89 



horsepower opposite the next lower velocity in Table I from 

 the horsepower opposite the next higher velocity. Mul- 

 tiply the difference by the quotient obtained'by dividing the 

 difference between the actual belt velocity as found from Table 

 III and the next lower velocity in Table I, by the difference 

 between the next lower and next higher velocities in Table I. 

 Add the product to the horsepower opposite the next lower 

 velocity than the actual. The sum is the total horsepower 

 transmitted by a belt of i sq. in. of cross-section at the 

 actual velocity. Multiply this sum by the cross-sectional area 

 of the belt to find the total horsepower. 



7. To find the maximum and minimum tensions for belts 

 at velocities intermediate to those given in Table I, multiply 

 the difference in tensions at the next higher and next lower 

 velocities to the actual velocity as given in Table I, by the 

 quotient found as described in the preceding paragraph. 

 If the tension as given in Table I at the lower velocity is 

 higher than the tension given for the next higher velocity, 

 subtract the product so found from the tension given in the 

 table for the next lower velocity. If the tension given in 

 the table is higher at the higher than at the lower velocity, 

 add the product to the tension given opposite the next lower 

 velocity. In either case multiply the sum or difference so 

 obtained by the area of the belt to ascertain the total maxi- 

 mum tension (t m ) or total minimum tension (/), as the 'case 

 may be. 



8. To ascertain the size of belt that will be required for 

 a given horsepower, determine the horsepower that a belt 

 of i sq. in. of cross-section will transmit under the con- 

 ditions of speed and arc of contact that exist, by the method 

 given in the first part of paragraph 4, or in paragraph 6. 

 Divide the figure so obtained into the horsepower to be 

 transmitted. This will be the cross- sectional area of the 

 belt. From Table VI find the maximum width of belt that 

 can be used on the pulleys given, and then opposite this width 



