and on Astronomical Refractions. 497 



The following table shows the constitution of the atmosphere 

 with this system of constants. ,It should be recollected that in cal- 

 culating this table, as well as those in p. 278 and p. 280, the law of 

 Mariotte and Gay Lussac, 



p = kq(\ + 0), 



is implicitly supposed to hold good at very low temperatures, which 

 is to a certain extent conjectural. For this reason, and for the 

 reason that we have not at present sufficient data for determining 

 with great precision the constants y and E t it is not intended to 

 attach precision to the temperatures, densities and pressures given 

 in the following table for the altitudes beyond 5 miles. The fol- 

 lowing example will serve to show how the table was calculated : 



Calculation of the Pressure, Temperature, and Density for the 

 height of 10 miles. 



log 10 = 1-0000000 i = 7-8546929 



log a = 3-5974758 in miles log M = 9-6377843 



7-4025242 



002526 

 7-4025242 

 log 1-002526 = 0-0011364 



7-4013878 

 8-2169086 



9-1844792 



}ogHq= 9-4725517 

 log H 9-7354232 



8-2169086 



152925 



9-8470750 = log (1 

 703194 

 296806 =Hq 



Hq) 



log (10) = 9-6571324 



2 



9-7371285 

 54592 = q 

 45408 = 1 q 



9-6571324 

 3 



1-2201080 

 ] gp = 0-4485185 



1-6686265 

 logg = 9-1613398 



T = [1-2201080] - - 448 C 



2-5072867 



321-6 



448-0 



T= 126-4 



Phil. Mag. S. 3. Vol. 17. Supplement, No. 113. Jan. 1841. 2 K 



