4 PROPERTIES OP STEAM AND OTHER VAPORS. 



C. For steam from 100 to 220 C, 

 log# - a - ba + c0\ 



* - 5-457430"34. 

 log 6 - 0.4119787931. 

 log c - 7.7417476470 - 10. 

 logcr - 9.99741106346 - 10. 

 log - 0.007642489113. 

 - t 100. 



To show the degree of accuracy attained, the following tables are 

 given: 



EQUATION B. 



LOG / FROM TABLE LOG / CALCULATED 

 OF LOGARITHMS. BY EQUATION. 



o 4-60 0.6627578317 



25 23.55 I.37I9009II5 1.37190097 



50 91.98 1.9636934052 1.96369346 



75 288.50 2.4601458175 2.46014587 



100 760 2.8808135923 2.88081365 



EQUATION C. 



LOG/ FROM TABLE LOG p CALCULATED 



** OF LOGARITHMS. BY EQUATION. 



ioo 760.00 2.8808135923 



130 2030.0 3-3074960379 3.307406036 



160 4651.6 3.6676023618 3.667602359 

 ioo 9426 3.9743274354 3.974327428 



220 17300 4.2402995820 4.240299575 



The results from Equation C are quite satisfactory; for the errors come 

 in the ninth place of decimals, and one place of decimals is unavoidably 

 lost in the application of the formula. Equation B was calculated after 

 Equation C and the numerical work was not carried to so large a number 

 of decimal places. For the calculation of tables, the constants are carried 

 to seven places of significant figures only; this gives six significant figures 

 in the result, of which five are recorded in the tables. 



Pressure of Steam at Latitude 45. French System. It is customary 

 to reduce all measurements to the latitude of 45, and to sea-level. The 

 standard thermometer should then have its boiling and freezing points 



