WHOLE VOL. NOTES. NORTH AMERICA 41 



Records the following corrections reduce pressure to 21 15 ft. but 

 do not include the correction to standard gravity. 



Pressure 

 True elevation correction * 



1892 2144 +.03 inch 



1907, July 5 2132 +.02 



1908, July 15 2147 +.02 

 1928, Apr. 1 2137 +.01 

 1930, Oct. 1, to 1932, Dec. 31 2147 +.02 



CENTRAL AMERICA 



COLON, CANAL ZONE 

 Authority. 



United States Weather Bureau, Washington, D. C. 

 Pressure. 



Means determined from hourly observations 192 1- 1928 and from 

 bihourly observations 1929- 1930. 



SAN SALVADOR, SALVADOR 



Authority. 



Observatorio Nacional, San Salvador. Continuation of obser- 

 vations published in volume 79, Smithsonian Misc. Coll. 



MEXICO 



Authority. 



Observatorio Central, Tacubaya. Continuation of the stations 

 published in volume 79, Smithsonian Misc. Coll., except 

 that Tacubaya is added and may in the future be substituted 

 for Mexico City. 



Pressure. 



The pressure data, when received, were not corrected for gravity. 

 The following corrections f are derived from the Smith- 

 sonian Meteorological Tables: Leon —1.2 mm, Mazatlan 

 — 1.4 mm, Merida —1.5 mm, Mexico City —1.2 mm, 

 Monterey —1.2 mm, Oaxaca —1.4 mm, Puebla —1.3 mm, 

 Tacubaya — 1.2 mm. 



* Correction on and after date required to correct station press, at 32° P. and Lat. 45° for 

 the elevation as given in World Weather Records. 



t These corrections were applied by the compiler except for Merida and Oaxaca where the 

 pressures as received agreed with those previously published in vol. 79. 



