Physical Department Notes.

The laboratory of Physical Geography has lately received a set of geographic models designed by Professor Albert Heim of Zurich, Switzerland. They represent an Alpine glacier, a mountain torrent, a bold coast line with branches and dunes, and a volcanic island of complex structure. Each model is about a foot and a half by two feet in size. All are delicately colored in remarkably natural tints giving an admirable combination of artistic and photographic effects. The model of the glacier represents a mountainous district with much variety and detail of structure and form, including two lofty gathering basins, where the snow is accumulated and converted into ice, and from which two unequal ice streams creep down, becoming confluent in a single valley further on. The various features of the scene are reproduced with great faithfulness, from the bergschrunds at the foot of the snow slides, to the seracs, crevasses, dirt bands, and moraines, the latter being tinted according to the rocks from which they are derived. Below the foot of the glacier, there are several abandoned moraines, one of which encloses a small lake. The rock ledges down the valley and on its slopes for a certain height above the ice are rounded and striated with surprising verisimilitude, indicating the former extent of the glacier. The model of the torrent illustrates the early stages of valley growth, when the little head water branch streams are gnawing backwards with great rapidity into the plateau country above them. Landslides are thus produced, several of them being indicated both in the incipient stages of undercut and semi-detached masses, and later their catas trophic fall. The detritus carried by the torrent is opened out in a broad fan-delta of gentle declivity across the bottom of a wider valley of greater age: and the river of this valley is thereby pushed against the further slope, where it undercuts the bank, forcing the highway to the upland. The volcanie island and the coast line are not less instructive.