204 A. W. Greely—Annual Address. 
tages of trade routes; navigation conditions, such as port dues, 
canal charges, lighterage, ete ; custom duties, both export and 
import; local trade methods; the character of currency and the 
peculiarities of exchange. As an illustration of the value of in- 
formation on the last-named point may be mentioned Stanley’s 
dismay at finding gold coin the only money recognized at Zan- 
zibar, while his gold sight bills on London or Calcutta were nego- 
tiated as a favor at the enormous discount of twenty percent. It 
may be said that elsewhere in Africa the friends of the white 
metal predominate, since in Abyssinia the Maria Theresa dollar 
(or five-frane piece) of a certain date—1789, I belieye—is the only 
current money, a fact which seriously threatened the success of 
the Abyssinian campaign until the British government supplied 
Austrian silver to its supply department. 
The extent of geographic science necessitates its division 
into distinct branches, which, by common consent, include, first, 
mathematical; second, physical, and, third, political geography. 
Among other suggested divisions are classical, climatological, 
historical, ete, which, in my opinion, are inadvisable, except as 
strictly subordinate divisions for special purposes. Other various 
and suggested divisions of economic, commercial, industrial, 
hydrographic and climatological should, in my opinion, be com- 
bined to form afourth branch to be known as economic geography. 
3 Mathematical geography concerns the figure, size and motion 
of the earth, its delineation on charts, and the determinations of 
its localities by astronomical methods. Research and instruction 
in connection with this branch should bear especially on the 
technology of geography, on the principles and methods of car- 
tography, and on such instruments, methods, etc, as are indis- 
pensable to the correct determination of positions. . 
Political geography considers the earth as divided into separate 
countries or states, the various methods through which these 
states subsist and exist as independent or subordinate govern- 
_ments, together with the affiliations and repugnances shown in 
their intercourse with other states. Under political geography 
should be studied the existing laws, moral institutions, social 
organization and modes of government of different countries, 
together with their domestic and foreign policies, with the ensu- 
ing results at home and extraneous influences abroad. 
Physical geography sets before us the characteristics of the 
surface of the earth, and in its entirety presents a concrete idea 
