DAVIS: THE HARVARD GEOGRAPHICAL MODELS. 
87 
Geographic Magazine for 1894, illustrating a part of the southern 
Appalachians. 
A third class of models includes those intended to represent ideal 
t} T pe forms rather than actual places. The best of these are found 
in a set of four, constructed by Prof. A. Heim, of Zurich, and 
duplicated for sale originally by Wurster and Co., now succeeded by 
J. Meier of the same city. Their price is about $20 without duty. 
They represent a high mountain district with snow fields and 
glaciers ; an Alpine torrent; a volcanic island ; and a cliff and dune 
coast. A number of these have been imported into this country by 
various colleges and are found of great service in teaching; but 
♦they have as yet made little or no impression on the schools. 
These four models are all independent of each other; each one 
tells its own story. Additions to the series from Professor Heim’s 
expert hand would be warmly welcomed by geographers. 
The models here figured fall into the same class as Heim’s, 
inasmuch as they are ideal type forms; but they stand in systematic 
sequence, and thus illustrate not only individual forms, but the 
relationship of different forms, and the principles of geographical 
evolution, a study which has been greatly advanced in recent 
years. I presume that others have designed models in series of this 
kind; but if so, they have not come to my notice. My own first 
considerable effort in this direction was in 1887, on the occasion of 
a series of lectures on physical geography in the Teachers’ School of 
Science, supported by the Lowell fund, and conducted under the 
auspices of the Boston Society of Natural History. The original 
clay models were constructed partly by myself, partly by Mr. J. II. 
Emerton, of Boston; and copies of all of them were made in paper 
by Mr. Emerton. They represented several series of land forms; 
for example, the valley of a degrading or eroding stream, with steep 
side slopes and narrow floor; the same district after a period of 
aggrading action, as a result of which the valley has been filled to a 
considerable depth, producing a broad flood plain ; the same district 
after the river has resumed its degrading action, sweeping away 
part of the valley filling, and producing terraces and locally super¬ 
posed falls, such as abound in New England to-day. Another group 
included five members, three in regular sequence and the other two 
in side branches. The first showed a plateau in an adolescent stage 
of dissection, the second in a mature stage, the third in an old 
stage. The fourth included a bay or drowned valley, produced by 
