MAPS AS GEOGRAPHICAL ILLUSTRATIONS 485 
necessary in order to interpret their meaning easily and accu- 
rately ; but their language is not difficult to learn. Next to a 
visit to different parts of the world, the study of these maps 
presents the best opportunity of gaining a real sense of the 
facts of geographical form with which Physical Geography has 
so largely to deal. In so far as they enable the student rapidly 
to generalize the individual facts slowly accumulated and 
recorded by many observers, they endow him with a power 
that could not be gained by field work without their aid, except 
by spending a very long time on the ground. 
This value of good maps is evidently not generally recog- 
nized or admitted, but it may be claimed and defended. It is 
as legitimate to base scientific discussions of fact and theory on 
good maps as it was for Loomis to base his great series of 
meteorological inductions on the records of our Signal Service. 
The failure to perceive this is indicated in a recent notice of an 
essay by C. Abbe, Jr.," in the Monthly Record of the (London) 
Geographical Journal for March of this year. Mr. Abbe’s essay 
dealt with the features and the explanation of the cuspate capes 
of our Carolina coast, his statement of fact being based on the 
Coast Survey charts. The explanation or theory of the origin 
of the cusps was entirely distinct from his inductions of gener- 
alized facts. The reviewer in the monthly notices, however, 
says: This essay appears to be ‘‘a purely theoretical discus- 
sion, not based on actual observations.” Truly it was not based 
on personal observations, but it was very carefully based on 
actual observations ; and in this respect it was, to compare small 
things with great, not “purely theoretical,’ but as truly scien- 
tific as Loomis’ famous studies. 
The habit of using maps, as far as travelers generally pos- 
sess it, is very largely based on familiarity with atlas maps, as 
studied in the school room or library ; and it is perhaps for this 
reason that explorers are so often content to bring home only 
narrative or locative accounts of their experiences, and so gener- 
ally satisfied to omit the systematic, rational, explanatory 
«Proc. Bost. Soc. Nat. Hist., XX VI, 1896, 489-497. 
