12 On the Prediction Tables for the Tides of the U. S. Coast. 
are simultaneous observations at some of the stations which were 
formerly examined with but little satisfaction as to the conclu- 
sions; these will now be resumed and may raion! additional 
light upon the results at some of the doubtful station 
The interference problems will be taken up err) more ex- 
tended data give better ee of a satisfactory solution of them. 
Art. Il.—WNotes on the Progress made in the Coast Survey, in Pre- 
diction Tables for the Tides of the United States Coast; by A. D. 
BacuHeE, Superintendent U. S. Coast Survey. 
(Communicated to be American Association for the pole arma of Science, by 
— of the oe Department.) 
Coast Survey, were directed to their reduction, chiefly by the 
graphical methods pointed out.by Mr. Whewell. "This work was 
subsequently continued by Mr. eres method, by Mr. Henry 
Mitchell: and next the tides of Boston harbor were taken up as 
affording certain advantages in as “observations themselves, 
which could not be claimed for those of Old Poin 
‘he system of Mr. Lubbock is founded on oe equilibrium 
theory, and in it the inequalities are sought by arranging the 
elements of the moon’s and sun’s motions, upon which they de- 
pend. Having obtained the co-efficient of the half monthly ine- 
quality of the semi-diurnal tide at Boston n, from seven years 
observations, through the labors of the tidal division, and approx- 
imate corrections for the parallax and declination, I was much 
disappointed in attempting the verification Bid ay applying the them to 
individual tides for a year during which bservations. 
There was a general agreement on the vara Ee discrepancies 
in the pagie cases, which were quite unsatisfactory. Nor were 
these pancies without law, as representing their residuals 
by curves did not fail toshow. By introducing corrections for 
declination and parallax of the moon increasing and decreasing, 
we reduced these discrepancies, but oe te results were nots 
cient approximations. With the numerical reductions of the 
observations before referred to, was i ouiiemans in 1853, under 
my immediate seee. by Mr. L. W. Meech, a study, of the 
theory of the tides chiefly to the works of Bernouilli, 
La Piace, Airy, Lubbock and Whewell. The immediate object 
