XIII. FORMS FOR TABULATIONS AND COMPUTATIONS 
Standard Forms 
In the tabulation of the tide record and in the computation of datum planes the 
work is facilitated by the adoption of standard forms. This permits of a uniform 
procedure, which, having been learned by the tabulator, reduces the time required for 
the tabulation and also lessens the chance of error. 
Both in the tabulation and in the computation of the tidal data the Coast and 
Geodetic Survey makes use of printed forms of uniform size, 8 inches wide and 10% 
inches long. ‘This size is a very convenient one for handling, and it is also convenient 
for filing, since no folding is necessary. 
Tabulation Forms 
Comparative readings.—The form used for tabulating the comparative readings, 
necessary with the standard gage, was discussed in Section IV, ‘‘Tabulation of the 
tide record,’’ and is illustrated, somewhat reduced, in Figure 17 (p. 38). The form is 
printed alike on both sides, one month being generally tabulated on each side. 
Hourly heights.—The hourly heights of the tide are tabulated on a form printed 
on both sides, each side accommodating a week of observations. This form likewise 
was discussed in Section IV and is illustrated in reduced size in Figure 15. The sums 
at the bottoms of the vertical columns permit the daily sea level to be determined, 
while the horizontal sums are used in the harmonic analysis. A check on the correctness 
of the vertical and horizontal sums is given by the final sum in the lower right-hand 
corner, which must check from the 7 vertical sums and from the 24 horizontal sums. 
The sum of the hourly heights for each month is entered on the last sheet of hourly 
heights of the month in the space provided for it at the bottom of the sheet, and the 
mean derived by dividing by the proper divisor for the month in question. The 
divisors for the various months are given on the sheet. 
The wide spacing on the form between the consecutive days is due to the fact that 
the tabulated hourly heights are used for summing component hours for the harmonic 
analysis by means of stencils. When this is not the case the form can be ruled to 
accommodate half a month on one side and the other half month on the other side. 
High and low waters.—The form used for tabulating the high and low waters is 
illustrated in Figure 16. The form is designed for one month of observations, the first 
17 days being tabulated on one side of the sheet and the remaining days of the month 
on the other side. The lunitidal intervals and the heights of high and low water are 
summed and the means derived as indicated, from which follow the range of the tide 
(Mn) and half-tide or mean-tide level (MTL). 
On the back of the sheet, illustrated in Figure 16, provision is made for the sums 
and means of higher high waters, lower low waters, and the inequalities of the month. 
A convenient method of summing the higher high and lower low waters directly from 
the sheet consists in checking each higher high and lower low with a small check mark. 
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