INVESTIGATIONS OF THE STEAMER ALBATROSS. 215 



height, a little open of the west tangent of Karpa Island when the 

 latter bore NW. A 1ST. (mag.) 11 miles distant. 



The Semidi Islands were sighted at daylight on the morning of Sep- 

 tember 13, and half an hour later Chirikof became visible. The accuracy 

 of the delineation of this island on the charts has been doubted by so 

 many navigators that we took the opportunity to verify it by steaming 

 along its south and east shores and taking angles on prominent points 

 until we satisfied ourselves that it was laid down practically correct. 

 The diverse opinions regarding the platting of this island may be 

 accounted for from the fact that passing vessels lay a course to clear 

 its southern extremity, which is high, and this carries them so far from 

 the long, low northern extension that they do not see it even in clear 

 weather. 



The Tiinity Islands were sighted at 3 p. m., and at 8 a. m. the follow- 

 ing morning, September 14, we took a departure from Ugak Island and 

 steamed offshore to intersect a rhumb line from Cape Greville to Cape 

 Edgecumbe, for the purpose of running a line of soundings between 

 those points, this course having been decided upon after a conference 

 with Captain Ludlow and at his request, which was based upon the 

 following experience of the U. S. S. Mohican while en route from Sitka 

 to Kadiak : 



At meridian, June 21, 1803, she was in latitude 57° 10' .1ST., longitude 

 143° 11' W., with clear, pleasant weather, and after running 10.4 miles 

 WSW. £ W. (mag.) was found to be in discolored water, with quantities 

 of seaweed and floating kelp; and although 1G0 miles from the coast, 

 appearances were so suspicious that they commenced sounding, but 

 found no bottom at 100 fathoms. Similar reports have been made of 

 discolored water, drifting kelp, etc., in various localities of the Gulf of 

 Alaska by sealers, whalers, and others, casting suspicion over the region, 

 which could be removed only by sounding; and as the Albatross was 

 the only vessel in the fleet having the necessary appliances, the senior 

 officer considered it advisable for us to make the examination. 



The first sounding of the series was made at 5.55 p. in., September 14, 

 in 838 fathoms, rocky bottom, latitude 57° 24' K, longitude 140° 33' W., 

 and the maximum depth, 2,741 fathoms, was found in latitude 57° 14' N., 

 longitude 148° 0G' W., in the great submarine depression lying south of 

 the Aleutian Chain and the Peninsula of Alaska. A depth of 2,099 

 fathoms was found in 57° 20' K, 143° 26' W., where the Mohican 

 encountered discolored water. The line developed a great basin with no 

 indications of shoaling water except at the terminals. 



In reporting the operations of the Albatross it is the intention to con- 

 fine ourselves generally to a simple statement of facts; yet it may not 

 be out of -place in this instance to call attention to similar phenomena 

 in other seas as a possible explanation of the appearance of discolored 

 water in various parts of the Gulf of Alaska. 



On the Atlantic and Gulf coasts of the United States patches of 

 discolored water have frequently been encountered man}' miles at sea 



