I IO 



The National Geographic Magazine 



PROGRESS IN SURVEYING THE UNITED 

 STATES 



MR O. H. TTTTMANN, Superin- 

 tendent of the U. S. Coast and 

 Geodetic Survey, in his official report for 

 1905, gives the following interesting sum- 

 mary of the year's work : "The most not- 

 able feature of the work of the year is the 

 completion of the line of precise levels 

 connecting the Atlantic Ocean and the 

 Gulf of Mexico with the Pacific Ocean. 

 The three principal connections with sea 

 level are at Sandy Hook, New Jersey; at 

 Biloxi, Mississippi, and at Seattle, Wash- 

 ington. The distance between Sandy 

 Hook and Seattle along the shortest line 

 of leveling of the highest degree of ac- 



curacy is 7,400 kilometers, and the similar 

 distance between Biloxi and Seattle is 

 5,700 kilometers. This leveling is a por- 

 tion of the precise-leveling operations 

 which will eventually furnish standard 

 elevations in the United States, upon 

 which the extensive operations of the 

 Reclamation Service can be based and for 

 use of geographers, civil engineers, and 

 surveyors, and for physical investigations 

 relating to the planet on which we live. 

 The leveling operations have been thor- 

 oughly checked by closed circuits as far 

 west as Norfolk, Nebraska, and the clos- 

 ure of the line westward on mean sea 

 level at Seattle, a distance of 3,300 kilo- 

 meters, with a small discrepancy which 



From U. S. Coast and Geodetic Survey 



Coast Survey Party Loading Outfit into Canoes, 1% Miles from Shore, Yukon 



Delta Coast, Alaska 



The bed of the ocean is so little inclined that each succeeding tide floods an area of many 

 hundreds of square miles. With the ebb this vast expanse is completely drained, and then pre- 

 sents to the eye an unbroken surface of mud and offers the traveler a most uninviting and difficult 

 footway. 



