288 GEOGRAPHICAL RESEARCH IN THE UNITED STATES 



was revived and has continued uninterruptedh' till the present 

 day. 



From the beginning its ideals were high. Great accurac}' has 

 ever been and is its motto. It has been a leader and not a fol- 

 lower. It has developed its own methods and instruments, and 

 to its officers, civil, militar}', and naval, we are indebted, among 

 other things, for the zenith telescope for the most accurate deter- 

 mination of latitudes ; for the application of the telegraph to 

 longitude determinations ; for the invention, construction, and 

 use of a machine for predicting tides, and for great improvements 

 in apparatus for measuring the force of gravity. Tlie pol3^conic 

 projection now so extensivel}^ used was developed and applied 

 by officers of this bureau, as also were appliances for deep-sea 

 sounding and the stud}' of the ocean deeps. 



Its field of work was extended in 1871 to include geodetic work 

 in the interior, and in 1876 it received the name of Coast and 

 Geodetic Survey, by which it is official!}' designated, though often 

 referred to as the Coast Survey. It is one of the active geographic 

 agencies of the United States, and is not only making charts, coast 

 pilots, and tide tables, but is contributing to our knowledge of 

 ocean physics, terrestrial magnetism, and of the size, shape, and 

 structure of our planet. 



Engineer Corps, U. S. A. — TheU. S. Engineers, though not now 

 actively prosecuting geographic research, have in the past made 

 notable contributions to geography. Prior to and even since the 

 war of the rebellion, 1861-'65, numerous expeditions in the far 

 west were made by army officers, and each of these added some- 

 thing to our geographic knowledge. Aside from these various 

 military reconnaissances two noteworthy surveys have been car- 

 ried on in the past by the U. S. Engineers. One was a surve}' of 

 the northern and northwestern lakes, which, after an existence 

 of forty 3'ears, was concluded in 1881. It made a series of de- 

 tailed and accurate charts of all the Great Lakes, and a valuable 

 collection of data. Its series of lake levels has very recenth' been 

 put to use in determining certain secular changes in the crust 

 of the earth forming the great basin in which those lakes lie. If 

 the slow tilting of this basin southward which these levels show, 

 when compared with recent ones, continues for a period of 

 about 6,000 years, then it is calculated that Niagara will have 

 vanished, and all the lakes except Ontario will drain to the Mis- 

 sissippi by way of the Chicago outlet. These highly interesting 

 and somewhat startling conclusions have just been presented at 



