116 
CHRISTIE. 
From these I obtained 
427-day distri¬ 
bution. 
440-day distri¬ 
bution. 
456-day distri¬ 
bution. 
Period.. 
d. d. 
437.6 ± 2.0 
d. d. 
437.0 ± 1.0 
d. d. 
437.7 =h 1.9 
<h . 
ft- ft- 
0.051 ± 0.007 
ft- ft. 
0.056 ± 0.007 
ft- ft. 
0.063 d= 0.008 
e i. 
219° ± 24° 
203° dr 12° 
170° d= 24° 
The date to which ^ relates is 0 h , July 1,1854, civil reckon¬ 
ing. The three distributions covered the period July 1,1854, 
to March 2, 1891, 38 years and 8 months. I took the mean 
of the three and wrote for result 
a x cos (i t — ej, 
with 
ft. in. mm. 
a x Eg 0.057 = 0.68 §= 17.3 
±7 ± 9 ±2.2 
= 197° 
±20 
i = 0°.03429 
±13 
Period = 437A 
±1-7, 
t reckoned in hours from 0 h , July 1, 1854, San Francisco 
mean local civil time. The superintendent communicated 
these results to the National Academy of Sciences at its ses¬ 
sion in Washington in April, 1892, and I included them in 
a paper read before the Philosophical Society on May 21, 
1892. 
Immediately upon the adjournment of the National Acad¬ 
emy I began the reduction of the tidal observations made 
at the Coast Survey mareograph station at Pulpit harbor, 
Penobscot bay, Maine, 1870-1888, and distributed them into 
three independent consecutive sections of five 440-day periods 
each, extending from 0 h , January 22, 1870, to 23 h , February 
16, 1888. The preliminary results, brought out without 
