Ivi INTRODUCTION. 



Table 65. Corrections to Table 64 for values of the acceleration of graV" 

 ity at sea level different from 9.80. 



This table is computed from a modification of equation (4) arranged 

 to give the increments of dynamic height corresponding to changes in g,p from 



9.80 m/sec". This form is //d= (0.980 /; — 1.543 x lO"' /r) + — — ~ — h 

 the latter factor being the increment. 



Corrections obtained from this table are applied to values obtained from 

 Table 64 for stations whose latitude is such that g,p differs from 9.80 ;n/sec-. 

 The side argument here is geometric height by intervals of 1000 m. and the 

 top argument is g^, the acceleration of gravity at sea level. Interpolations 

 must be made for geometric heights which are not in even km. and for values 

 of g,p which lie between the values given at the top. 



Table 66. Normal value of the acceleration of gravity at sea level. 



This table has been computed by means of the U. S. Coast and Geodetic 

 Survey Formula 



^0 = 9.80621 ( I —0.002640 cos 2 (^ + 0.000007 cos- 2 ^) 



where 



^0= normal value of acceleration of gravity in m/sec~ at latitude ^ at sea level. 



and <j)= latitude in degrees. 



The side argument is latitude by intervals of 10°, and the top argument 

 is latitude by unit degrees from o to 9. Thus the value of gtp may be obtained 

 for every degree of latitude. For stations whose latitude cannot be expressed 

 in whole degrees, interpolations may be made for fractional parts of degrees, 

 or reference may be made to Table 90. 



Table 67. Heights reduced from dynamic meters to geometric meters, 

 the acceleration of gravity being 9.80. 



This table, computed by means of equation (8) converts dynamic heights 

 to geometric heights, where (70=9.80 vi/stc-. The side argument is dynamic 

 height by intervals of 1000 dynamic meters and the top argument is dynamic 

 height by intervals of 100 dynamic meters. A proportionality table is added 

 as in Table 64. 



Table 68. Corrections to Table 67 for values of the acceleration of grav- 

 ity at sea level different from 9.80. 



This table is computed from a modification of equation (8). The modi- 

 fied form employed is 



(8a) h= (-^//,+ i.637Xio-^//^) + 9-^g~^^ H, 



^ ^ \9.80 ^ / 0.98 g^ 



