C. Abbe— Computation of Relative Altitudes. 31 
path is generally taken to Katahdin Pond, and south to the 
mountain, though I should prefer the route up the Wassata- 
cook to the place where Katahdin comes down to this stream, 
and so up the mountain from the north, where it is easier of 
ascent. Before the summit is reached in this direction, there is 
a chance to camp in the mixed growth of trees; and startin 
early, you can get over the top of the mountain without that 
exhausting labor which attends ascent by the other routes. 
The magnificence of this mountain is not appreciated without 
a visit to it. Its base above the surrounding country running 
north and south must be nearly ten miles. long, and its top in 
this direction not far from six miles) The summit is in 
general flat, though having several peaks. 
* 
Art. VIL.—Table for the Computation of Relative Altitudes; by 
CLEVELAND ABBE. 
su 
published by Diffe in Schumacher’s Jahrbach, and be b 
measure common y used in the United States. I have not 
altered the contents given in the Smithsonian edition, but have 
extended the tables to @frange sufficient to cover several extreme 
cases that have come to my notice. The daily use of the baro- 
meter in this country for hypsometrical determinations, leads 
me to think that the tables here presented will be as convenient 
to others as they have proved to myself. 
he directions for the use of these tables are not different 
from those eve on pages 54-57 of Section D of the se 
log A=log u+Atete? 
where u=log b—log b' 
and ¢ and c' are the small corrections for the change in the 
force of gravity with the latitude and the altitude respectively. 
Washington, Nov., 1871. 
