198 National Geographic Magazine. 
The cruise of the Thetis was remarkable in several respects, 
among others in that, thanks to the open season, her stanch build, 
and successful battling with the ice-pack, she was enabled to reach 
Mackenzie bay, in British North America, the first government 
vessel to carry the American flag in those waters. She also. 
made the long stretch from Mackenzie bay to Herald island 
and Wrangel land in one season, never before done, and she 
had the honor of being the first vessel of any kind to follow 
the entire main coast line of Alaska from Port Tongass, in 
extreme southeastern Alaska, to Demarcation point, in the 
Arctic ocean. 
