X 
introduction. 
were confined to one spot. Of the merit of the drawings made by 
Lieutenants Beechey and Hoppner, I am not a competent judge, 
further than as regards the accuracy and faithfulness of the delineation ; 
and to this I am anxious to bear the most unqualified testimony, 
no less than to the zeal and industry displayed by these gentlemen, 
whenever opportunities olfered of performing this branch of their 
duty, in compliance with their Lordships’ Instructions on that 
head. 
The Charts contained in this volume, comprising surveys of every 
coast visited by the Expedition during the voyage, are reduced 
from those drawn on board the Hecla' under my immediate in- 
spection, by Mr. Bushnan, Midshipman of that ship, a gentleman 
well skilled in the construction of charts, and in the art of marine 
surveying. The original charts are lodged in the Hydrographical 
Office of the Admiralty, together with a detailed account of all 
the angles and other materials used in their construction. As it 
was known that no reliance could be placed on the compasses from 
the spot where our discoveries commenced (namely, from the 
entrance of Sir James Lancaster’s Sound, westward), it was deter- 
mined, from the first, altogether to reject magnetic bearings in 
the construction of the charts, using only those deduced astrono- 
mically from the sun’s altitude and azimuth, together with its angular 
distance from the object whose true bearing was required. Astro- 
nomical bearings were always thus obtained at the same time with 
observations for latitude and longitude. Whenever it was considered 
expedient to take them at other times, the log was of necessity re- 
sorted to, in order to obtain the ship’s place from the nearest 
observation; and when this time happened to fall nearly midway 
