146 
HYDROGRAPHY IX THE EXITED STATES 
anything “ until these tourists began making such a fuss over 
the glaciers.” Not one of them, however, had ever heard of 
Lieutenant Wood’s visit in 1877, two years before Mr Muir and 
one year before the mythical miners. 
HYDROGRAPHY IN THE UNITED STATES 
By Frederick. PI. Newell, 
Chief Ilydeographer, United States Geological Survey 
Hydrograph}' has been defined as that branch of the science 
of i)hysical geograjdiy which ])ertains to the waters of the earth’s 
surface. The river systems, the annual regimen of the streams 
and their function in sculpturing the land, the lakes with their 
fluctuations, and the oceans with their tides and currents, all 
come within the province of the hydrographer. In the United 
States explorations and discoveries in this lu’anch of geography 
are being made largely through surveys carried on by the P'ed- 
eral Government througli its various executive dejiartments — as, 
for instance, the Coast and Geodetic Survey, a bureau of the 
Treasury Deiiartment ; the Geological Survey, a part of the De- 
partment of the Interior, and others. In common use, especially 
among mariners, the term hydrograpliy is understood as per- 
taining only to marine surveying and charting, but as employed 
in scientific usage it embraces far more than the knowledge of 
the coa.sts and includes all waters, without reference to naviga- 
tion, thus covering the continents as well as the oceans. 
In tracing the order in which these hydrographic surveys are 
being made by the various organizations or Imreaus of the gov- 
ernment, it may be well to begin with the waters as they first 
occur upon the land and trace them downward in their course 
to the ocean. First in this system comes the Weather Bureau, 
which measures and records the precipitation at various j)laces. 
From these data certain general deductions can be made regard- 
ing the h}'drography of the country, Vmt the operations i)ertaining 
more directly to this subject are those incident to the prediction 
of floods along important streams. For this pur])ose the Weather 
Bureau maintains river gauges at various points, the observers 
reporting the height of water at certain intervals, and at times of 
threatened floods telegraphing the facts regarding the behavior 
