urs. From these readings Mr. Giffin makes the
altitude of the mountain twenty thousand three hundred and seventy-four
feet above Valdez, which is ten feet above the sea-level. From this
result Mr. Giffin is disposed to question the accuracy of the reading at
Gibbon, though the author has no reason to doubt it was properly and
carefully made. Valdez is much farther from the summit than Fort Gibbon
and is in a different climatic zone. The calculation from the Valdez
base should, however, be taken into consideration in making this
barometric determination, and the mean of the two results, twenty
thousand six hundred and ninety-six feet, or, roundly, _twenty thousand
seven hundred feet_, is offered as the contribution of this expedition
toward determining the true altitude of the mountain.

The figures of Mr. Giffin's calculations touching the altitude of this
mountain and also determining the altitudes of various salient points or
stages of the ascent of the mountain are printed below:

DENALI (MOUNT McKINLEY)

USING AIR THERMOMETER READING +7 deg. AND THE READING
AT FORT GIBBON FOR SAME DATE

Mount McKinley, barometric reading 13.617 in.
Barometer reduced to standard temperature +.027 " Temp. 7 deg.
------
13.644 in.

Fort Gibbon, barometric reading 29.590 in.
Barometer reduced to standard temperature -.128 " Temp. 76.5 deg.
------
29.462 in.

Mount McKinley, corrected barometer 13.644 in. 21,324 ft.
Fort Gibbon, corrected barometer 29.462 " 400 "
------
20,924 ft.

Mean temperature, 41.7 deg.--approximate
difference in elevation 20,924 ft. -356 ft.
Latitude, 64 deg.--approximate difference
in elevation 20,568 " +15 "
Mean temperature, 41.7 deg.--approximate
difference in elevation 20,568 " +71 "
Elevation lowest, 400--approximate
difference in elevation 20,568 " +20 "
------
Elevation above Fort Gibbon 20,674