PREVIOUS EXPLORATIONS. 25 



subtend an angle of about 22 minutes, which was measured with the micrometer 

 screw of the alidade. 



Between stations a traverse of the river was made with prismatic compass and 

 stenometer. The plat of the traverse was transferred to the plane-table sheet 

 and fitted to the located points. The orientation of the plane table was controlled 

 bv the azimuths, determined with the theodolite when necessary. 



The method of plane-table locations was followed from Bergman to a point 20 

 miles beyond the summit, and, judging- from intersections on points on either side of 

 the route, it was satisfactory and sufficiently accurate for the publication scale of the 

 accompanying exploration map. The compass and stenometer were used from a 

 point 20 miles beyond the summit to the end of the traverse, on the Arctic coast. 



PREVIOUS EXPLORATIONS. 



HISTORICAL SKETCH. 



Soon after the discovery of America interest was awakened in, and attempts began 

 to be made to find, a northwest passage from the Atlantic to the Pacific Ocean, and 

 these led directly or indirectly to explorations of Alaska and adjacent regions. The 

 discovery of the northwestern side of America, and especially of the Arctic coast 

 of Alaska, was preeminently the work of the English and the Russians. 



For the benefit of the reader who may desire to extend his knowledge on this sub- 

 ject, a list of works from which much of the information here compiled has been 

 drawn is given at the end of this chapter. Though the following sketch aims to 

 note the more important of these discoveries and explorations, it does not attempt 

 to be exhaustive. 



Samuel Hearne," of the Hudson Bay Company, reached the Arctic Ocean as early 

 as 1770 by way of Coppermine River, in longitude approximately 110°. His jour- 

 ney was considered as demonstrating the practicability of reaching the coast by this 

 route and means of travel, and, what was of much greater importance, the absence of 

 any waterway connecting Hudson Bay with the Pacific Ocean. 



In 1778 Captain Cook's expedition, 6 composed of the vessels Resolution and Dis- 

 covety, in search of the northeast passage, explored the northwest coast from Norton 

 Sound to latitude 70° 41', a little north of Icy Cape, where they were obliged by the 

 ice pack to turn back. The conclusion reached at this time (and the correct one it 

 afterwards proved to be) was that no passage existed south of latitude 65°, and that 

 it must be sought north of Icy Cape. 



In 1789 Sir Alexander Mackenzie, a member of the Northwest Trading Com- 

 pany, descended to the mouth of the great river which bears his name. In its delta he 



aHeame, Samuel, A Journey from Hudson's Bay to the Northern Ocean, Dublin, 1796, p. 162. See also Barrow's 

 Arctic Regions, p. 300. 



b Cook's Voyage to the Pacific Ocean, 3 vols., London, 1785, vol. 2, pp. 146465. 



