BAROMETRICAL MEASUREMENT OF HEIGHTS. 395. 



In Table III., for A, with the argument v, take c', which, in this case, is always 

 positive ; then, remembering that the values of c and c 1 are given in units of the 

 fifth decimal, we have, 



v -|- c -(- c 1 = log h in toises, 



v + c + c' + 0.28982 log h in metres, 



v -j- c -j- c 1 -\- 0.80584 = log h in English feet. 



Example 1. 



L. station B = 329.013 Paris lines ; T = +15.88 R. ; t = + 15.96R. ; < = 45 32. 

 U. station B' = 268.215 Paris lines ; T' = -f 8 - 40 R - J * = + 7.92 R. 



* + i' = 23.88 R. 



log B = 2.51722 10 X 15.88 = 2.51563 

 log B = 2.42848 10 x 8.4 = 2.42764 



u = 0.08799 



log u = 8.94443 



A= 3.99982 



v = 2.94425 

 c = _ 0.00002 

 c' = + 0.00012 



log h = 2.94435 



h = 879.74 toises. 



Example 2. 



L. station B = 763.15 millimetres ; T = t = 25.3 Cent. = 20.24 R. ; = 21. 

 U. station B' = 600.95 millimetres ; T' = t' = 21.3 Cent = 17.04 R. 



t + t' = 37.28 R. 



log B = 9.88261 10 x 20.24 = 9.88059 

 log B' = 9.77884 10 x 17.04 = 9.77714 



u = 0.10345 

 logw = 9.01473 

 A = 4.01337 



v = 



c = + 0.00084 



c' = + 0.00014 



log h = 3.02908 for toises. 

 0.28982 



log h = 3.31890 for metres. 

 log h 3.02908 for toises. 

 0.30584 



log h = 3.83492 for English feet. 

 h = 1069.3 toises = 2084.0 metres = 6837.9 English feet. 



D 55 



