404 
A r P E N D I X NO. X. 
same time have iu some instances received a proportionate correction, 
obtained from the check of any single line directly from comparison 
■with astronomical data. At other times, distances paced were found 
to agree remarkably well with their distance astronomically determined. 
In this way a journey undertaken in March, 1854, was found correct 
to within ouc-thirticth of the whole distance travelled over in six 
days. 
The survey of bays and harbors was conducted in the ordinary way 
by means of a base-line, measured either with a cord properly stretched 
or by pacing. Angles were then measured at each extremity, and 
occasionally another point was determined trigonometrically. The head¬ 
lands, prominent bluffs, and islands for these maps generally were 
determined astronomically. 
The above exposition refers to a complete horizontal survey; but 
the measurement of prominent elevations was not neglected. This 
was done by means of a base-line parallel with the foot of the cliff, and 
the measurement of the necessary angles. Some barometric altitudes 
were obtained with ah aneroid,—an instrument peculiarly fitted for 
such measurements, and which was compared with a mercurial baro¬ 
meter before leaving and immediately after returning to the brig. 
In one instance, in March, 1S54, the aneroid for a short time after 
returning on hoard pointed to the same mark which it had indicated 
while on the top of the cliff. It had there been exposed to a tem¬ 
perature of 50° below zero; and, after the instrument had attained its 
former higher temperature, the index returned to its proper place within 
one-hundredth of an inch. 
The whole survey, made as explained above, embraces that portion 
of the coast north of Capes Alexander and Sabine. That portion of 
it included between Cape Alexander and Upcrnavik, which was in 
revision of the work of our English predecessors, as laid down in the 
Admiralty charts, was made during the escape of the party in boats. 
For the greater portion of this labor I am indebted to Mr. Sontag. 
E. K. K. 
