Climatic Changes Indicated by Glaciers.— Russell, 331 
the northern lateral moraine. This moraine must, until very recently, 
have been backed up by the glacier itself, though the front of the latter 
has now retreated two miles to the eastward. 
While the fact of recession is manifest, the rate is more difficult to de- 
termine. In one case, however, it is possible to connect the amount of 
recession with an important episode in the history of the region, namely, 
the eruption of a wide spread deposit of volcanic ash which extends 
from near the head of the Pelly westward to Scolai pass. With regard 
to the age of this deposit Dr. Dawson says:* “While the eruption must 
have happened at least several hundred years ago, it can scarcely be 
supposed to have taken place more than a thousand years before the 
present time.” 
For a distance of about three miles in front of the Klutlan glacier 
there is a deposit of moraine material perhaps 200 feet thick, composed 
of volcanic ash and angular rock fragments. This evidently fixes the 
position of the glacial front at the time of the volcanic eruption, and the 
amount of recession since that event. It is interesting to note that on 
the present glacier surface the volcanic ash is found only ashort distance 
from the end, showing that since the eruption, while the front of the 
glacier has receded about three miles, nearly the whole mass of the 
glacier has been renewed by fresh addition from its source. 
The single exceptional case already referred to, is the Frederika gla- 
cier, which seems to be advancing its front instead of retreating. It has 
its source in the high mountains forming the eastern members of the 
Wrangell group, and flows south in a lateral valley, joining the valley of 
the Nizzenah at right angles. The front of the glacier is parallel with 
the river and about three-fourths of a mile from it, the intervening space 
being a gravel plain. The glacier terminates in a nearly vertical ice 
cliff about 250 feet high. It is slightly convex, and stretches entirely 
across the valley abouta mile in length. The surface of the glacier is 
free from moraines but is extremely rough and broken, unlike the ordi- 
nary surface of stagnant ice at the end of a retreating glacier. At the 
foot of the cliff is a small accumulation of gravel and fragments of ice, 
probably pushed along by the advancing mass.t 
An explanation of this anomalous case is suggested. Ten miles to the 
westward of the Frederika another much larger glacier flows into the 
valley of the Nizzenah. This is formed by the union of three separate 
Streams, and of these the eastern appears to be retreating much more 
rapidly than either of the others. But this eastern branch probably has 
its source in the same basin as the Frederika glacier, and it seems not 
impossible that by some means the drainage has been diverted from the 
western to the eastern outlet, thus causing the rapid retreat in the former 
glacier and advance in the latter. 
*Report on Yukon District, p. 45 B. 
This is the only instance of an advancing glacier known on the west 
coast of North America. I. C. R. 
