62 
ALASKA GLACIERS 
the tidal arm has raised doubts as to the correctness of 
the first impression, and I now suspect that it was only 
the remnant of a former arm of the glacier, stranded as a 
motionless and slowly wasting summit mass. On the map 
of the Canadian Boundary Commission (1895) it is repre¬ 
sented as a distributary of the glacier. 
At the time of Russell’s visit in 1891 the glacier flowed 
on both sides of the high rock knob (fig. 34) and was re¬ 
united beyond it, so as 
to convert the knob into 
a nunatak; and it was 
this conspicuous nuna- 
tak near the end of the 
glacier which 
its name. The retreat 
of the ice front in the 
intervening eight years 
can not have amounted 
to less than a mile and 
may have been twice as 
great. It was nearly all accomplished in the first half of 
the period, for the photographs made by the Boundary 
Commission in 1895 1 show a complete separation of the 
two arms and a close approximation to the condition of 
1899. The tidal arm was perhaps a third of a mile more 
advanced in 1895, but the non-tidal was not appreciably 
longer. It is possible, however, that the latter extended 
for some distance in a stagnant condition beneath a mantle 
of drift, for at the time of our visit there appeared to be 
remnants of ice in a moraine belt stretching for a mile be¬ 
yond its extremity. 
The accompanying map (pi. vn) is based on the sur¬ 
vey by Gannett in 1899, supplemented by photographs. 
It is accurate as to the ice front and contiguous land, but 
1 Nos. 20 and 45, on pages 7 and 17 of vol. 17 of the official album. 
FIG. 34. TIDAL FRONT OF NUNATAK GLACIER. 
Photographed from the north, by D. G. Inverarity, 
June 21, 1899. The camera stood on the glacier. 
