OCEANOGRAPHY OF THE PACIFIC. 6 



TRACK. ' 



It would be unnecessai'}^ for the purpose of this study to attempt to 

 present in detail the exact courses followed by the vessel, which were 

 at times quite erratic, in the effort to find the most feasible location 

 for the cable. It is to be understood, therefore, that the accompany- 

 ing track charts do not represent the exact courses of the ship nor the 

 line determined upon for the cable or followed in the laying of it. 

 The stations charted, however, are supposed to be accurately located. 

 Before preparing the charts certain stations on the outward voj^age 

 were selected for careful examination of bottom material. The con- 

 siderations governing the selection were chiefly the depth, the macro- 

 scopic appearances of the bottom specimens, and the distances. These 

 stations were afterwards plotted and connected by a continuous line. 

 In a few instances outlying stations of especial interest have been 

 indicated on the charts, and a serial number and depth given for each. 

 On the first or diagrammatic chart the station numbers included 

 within each five degrees of longitude or latitude are given for both the 

 outward and homeward voyages. By means of this index it is easy to 

 locate approximately any station mentioned in the record. 



DEPTHS. 



The graphic representation of the contour of the ocean bed along 

 the course of this survey is less simple and satisfactory than usual, 

 because of the breadth of track explored and the large number of 

 soundings recorded. It should be noted, in examining the contour 

 charts appended, that-the lines are drawn from the localities indicated 

 on the track charts as stations selected for special examination of 

 bottom material, and one of the principal determining factors in the 

 selection was that of depth. Therefore, the contour charts may be 

 said to represent the extremes of elevation and depression along the 

 main line of the outward voyage only, without taking into account 

 intermediate or outlying irregularities of surface. The omitted sta- 

 tions can be easily supplied from the record if greater detail is desired. 



Leaving the island of Oahu of the Hawaiian group, the depth 

 increases quite rapidly until it reaches about 2,500 fathoms. This 

 depth is reached less than 30 miles due north of the island. ' From 

 this point nearly to Midway Island there is a comparatively level 

 plain, broken only by two or three outlying peaks from the moun- 

 tain range whose highest summits show themselves as small islands or 

 reefs a little to the westward of the line of survey. One of these 

 peaks appears at station 93, where there is a sharp rise to 1,463 

 fathoms, which, however, as rapidly falls away to the normal level a 

 few miles to the northward. A smaller projecting spur is indicated at 

 station 106, 2,002 fathoms. Another sudden rise to 1,726 fathoms 



