Loss of Heat from Covered Steam Pipes 15 



idea of what allowance to make for any covering when in a posi- 

 tion exposed to strong drafts. 



SUMMARY OF TESTS 



TABLE OF VALUES OF C 



Before analyzing the meaning of the results shown in this 

 table, it is best to recur to the method by which these figures 

 were obtained. We have already shown this using as an example 

 Mr. Barrus' test of magnesia covering on a 2 -inch pipe. 



We will now assume an error of 5 per cent, in the condensa- 

 tion, then instead of 96.2 B. T. U. per foot run we will have 101. 

 Then 101 = 1.15X1.6 (/ 64.6) 

 and t' = 120 instead of 117. 

 101 X .61 



Then C =- 



12 = .481 



6.28 X 245.2 



We found before that C = .453. An error of 5% then in 

 the experiment causes an error of 6 T 2 7 per cent, in the computed 

 value of C. 



Our object in examining these experiments was to prove 

 that Peclet's theory was in agieement with them, or perhaps it is 

 better to say that we wish to prove that, having determined by 



