XIV LETTER OP TRANSMITTAL. 



Some of the tables have been prepared in this office ; others have been 

 compiled from various sources, notably from appendices to reports of the 

 U. S. Coast and Geodetic Survey and "Lee's Tables and Formulae." 

 Very respectfully, 



Henry Gannett, 



( 'hief Topographer. 

 Hon. J. W. Powell, 



Director U. S. Geological Survey. 



