s bitterly cold, yet my fingers, though numb, were usable when I
reached the top; it was in exposing them to manipulate the hypsometrical
instruments that they lost all feeling and came nigh freezing. And
breathlessness was naturally at its worst; I remember that even the
exertion of rising from the prone position it was necessary to assume to
read the barometer brought on a fit of panting.

[Sidenote: Calculations for Altitude]

With these circumstances in mind we will resume the discussion of the
readings taken on the summit and their bearing upon the altitude of the
mountain. It seems right to disregard the temperature recorded for the
attached thermometer, and to use the air temperature, of which there is
no doubt, in correcting the barometric reading. So they stand:

Bar. Temp.
13.617 inches 7 deg. F.

The boiling-point thermometer stood at 174.9 deg. F. when the steam was
pouring out of the vent.

They stand therefore:

_Gibbon_ (334 feet altitude) _The Summit of Denali_
Bar. Ther. Bar. Ther.
29.590 76.5 deg. F. 13.617 7 deg. F.

Now, the tables accessible to the writer do not work out their
calculations beyond eighteen thousand feet, and he confesses himself too
long unused to mathematical labors of any kind for the task of extending
them. He was, therefore, constrained to fall back upon the kindness of
Mr. Alfred Brooks, the head of the Alaskan Division of the United States
Geological Survey, and Mr. Brooks turned over the data to Mr. C. E.
Giffin, topographic engineer of that service, to which gentleman
thankful acknowledgment is made for the result that follows.

[Sidenote: Fort Gibbon and Valdez as Bases]

Ignoring a calculation based upon a temperature of 20 deg. F. on the
summit, and another based upon a temperature of 13.5 deg. F. on the
summit (the mean of the air temperature and that recorded for the
attached thermometer) and confining attention to the calculation which
takes the air temperature of 7 deg. F. as the proper figure for the
correction of the barometer, a result is reached which shows the summit
of Denali as twenty-one thousand and eight feet above the sea. It should
be added that Mr. Giffin obtained from the United States Weather Bureau
the barometric and thermometric readings taken at Valdez on 7th June about
the same length of time after our reading on the summit as the reading
at Gibbon was before o