678 EXPEDITION TO POINT BAEEOVV, ALASKA. 



A piece of cod line was stretched along the face of the scale and led through an ivory stud 

 attached to the counterpoise. This ivory stud coincided with the zero of the vernier or reading 

 index. On either side of this stud cork slides were attached to the cod line and were pushed one 

 up, the other down, witli rising and falling tide, respectively. Attached to these corks were brass 

 verniers moving along the scale and enabling close readings to be made. The highest and lowest 

 readings of the sea-level falling between the regular halt-hourly observations were thus 

 automatically recorded. 



Location of gauge. The gauge was placed on the shore ice due west from the station and 

 at a distance of about 100 yards from the beach. The water at the hole was 17 feet deep at mean 

 low water. The ice was level, and at the beginning of observations in February \va.s 4-J, feet thick 

 and at the close of observations in June was 5 feet thick. 



About one mile and a half from the beach and parallel with it is a bar having about: 3 fathoms 

 water upon it. On this bar the heavy pack-ice grounds and thus leaves the inshore ice compaia- 

 tively undisturbed. During this entire series of observations the, ice remained undisturbed except 

 in elevation. The anchor remained unmoved and the line hung free in the middle of the hole. 

 The accumulations of ice on the side of the hole were chopped away each day. That the ice, how- 

 ever, rose and fell was obvious, independent of the gauge readings, for along the u ice foot " at the 

 beach the rise and fall was clearly seen, though there was never open water between the beach and 

 the gauge, except for a few moments when the general level of ice would break oil' from the " ice 

 foot " witli falling or rising tide and make a narrow seam, which was soon after solidly frozen over. 



In this location the gauge was practically free from local peculiarities and so disposed as to 

 give the fluctuations of level in the open ocean. 



Time. The observations were made on local mean time. At intervals of one, two, or three 

 weeks, as the weather permitted, time observations were made with transit or sextant, for the reg- 

 ulation of the standard chronometer upon which all other time-pieces depended. 



Flood tide.s came from the southward and west ward and there was a prevailing current, setting 

 to the northeast. The ebb current slackened but did not reverse this current. 



The daily rise and fall of tide is quite small, being about 6 or 7 inches, but during the series 

 of observations the level of the sea varied more than 3 feel. 



'i he duplicate record has been placed in tbe hands of the superintendent of the Coast and 

 Geodetic Survey for reduction, discussion, and publication. A preliminary discussion has been 

 made, from which enough of the peculiarities of these Arctic tides have been brought out to show 

 that a more complete analysis, study, and comparison with other Arctic tides is desirable. It has 

 been deemed desirable to substitute here the original record of observations for this preliminary 

 discussion and to give the full discussion hereafter. This discussion will be made and published 

 by the Coast and Geodetic Survey. 



