THE LATITUDE-VARIATION TIDE. 
117 
correcting for imperfect elimination of other tides, orally 
reported to the superintendent May 21,1892, and communi¬ 
cated to the Philosophical Society in my paper that evening, 
are given below in the recapitulation. 
About February, 1893, I resumed work on this tide, re¬ 
vised the computations, and rewrote my official report for 
publication in the Coast Survey annual volume. It was 
practically finished when I was forced to resign, April 18, 
1893. This paper contained the development of the formulae 
of reduction, a description of the data, the record of spirit- 
levels at the mareograph stations, the derivative ordinates 
(eight to each period), like ordinates for each section, tables 
of the computed corrections, the corrected results, and sug¬ 
gestions for the further prosecution of the work in a less 
expensive manner. I have not succeeded in having this 
paper produced, nor the one of which it was a revision; the 
data which I now have are too scanty and fragmentary to 
enable me to rewrite it, even if I had the time to give to it. 
I have lately, however, at great inconvenience to myself, 
gone over everything relative to the San Francisco tides 
accessible to me. There is, in my opinion, a second term 
of the latitude-variation tide, with double speed and half 
period, and with a range about half that of the first term, 
but the use of the records of the tidal division would be 
necessary to enable me to determine its period without 
ambiguity. It may also be remarked that the ordinates of 
the 440-day distribution at San Francisco can be easily 
thrown into three consecutive twelve-year periods and super¬ 
posed, with a view to bringing out a tide corresponding to 
the twelve-year term of the latitude-variation discovered by 
Dr. Chandler. 
The revised results follow. The epochs are given for the 
corresponding date, which is the mean local civil date of 
the middle of the series treated. The Julian dates are local 
astronomical. All these dates, with the other quantities, are 
given with greater precision than the nature of the results, 
if they were to stand alone, would warrant; but they are for 
comparison with other results. The San Francisco mareo- 
