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BURTON E, LIVINGSTON AND EDITH B. SHREVE 



average was compared with the theoretical response time for that 

 temperature, as calculated from the average of 30 tests at 24.8°C. 

 The results obtained, together with the corresponding calculated 

 and experimentally derived values, are given in table 1. 



TABLE 1 



Time periods required for color change of hygrometr,c paper slips over standard 

 evaporating surface at various temperatures as obtained experirnentally and as 

 calculated from the period required at 2^.8°C. All tests at each temperature are 

 represented by a single average 



* "According to Regnault, Broch and Weibe," as given in Van Xostrand's 

 chemical annual, edited by J. C. Olsen, 2d issue; New York, 1909. (Table 

 Ixxix, p. 436.) 



From the percentage variations in the last column of table 1 

 it is seen that the averages derived from direct observations 

 and the values calculated from the average for 24.8° are generally 

 in exceedingly good agreement. It is frequently found that 



