TIDAL DATUM PLANES Silt 
tenth giving the highest and lowest readings. The place on the curve to which the 
time and height note pertains is indicated by a vertical line. 
On the first day of each month the tide roll is taken off the gage and a new roll 
_put on. The observer notes on the roll the name of the station, the reduction-scale of 
the gage and the kind of time used. The roll is then ready for tabulation. 
Were arsivernye 
nn (AIS eommminmn geen 
wee GAGE TIME ZED. 
TRUS se 
STAFE READING con Deen tan Mut roveeen 
CORRECT TIME «0.4.4.2 4% 
Fic. 14.—Tide curve from standard gage, and comparative note. 
