Towns > Glasgow > 1828-1912 - Post-Office annual Glasgow directory > 1867-1868

10
ALMANACK AND TIDE TABLE.
EXEMPLIFICATION AND CONSTRUCTION OF THE FOLLOWING TABLES.
TO FIND THE TIME OF HIGH WATER AT ANY PLACE IN THE GENERAL TIDE TABLE.
Rule. — To the time of high water at Glasgow on the givea day, add or subtract the correction for the
required place as stated in the table, and the time of high water will be obtained. When the 'sum of the
correction, and of the time of high water in the table exceeds 12 hours, subtract 12 hours, and the remainder
will be the time of high water in the morning or evening of the given day, as the column denotes ; when
the sum of the former quantities is less than 12 hours, this sum will be the time of high water required in
the evening of the preceding day, or the morning of the given day, according as the column is marked
morning or evening. Or the morning and the evening tides may be found thus : — If the morning tide be
sought, and the sum be above 12 hours, take the time from Glasgow for the preceding evening, to which
add the correction for the required place ; from the sum subtract 12 hours, and the remainder is the morning
tide at the place required. If the evening tide is wanted, and the sum exceed 12 hours, take the Glasgow
morning tide for the given day, to which apply the correction for the required place, from the sum subtract
12 hours, and the remainder is the evening tide at the place required.
Required the time of high water at Peterhead, May 12th, 1868. H. M.
High water at Glasgow, May 12th, 4 40 a.m.
Correction for Peterhead, 1 3
High water at Peterhead, 3 37 a.m.
Required the time of high water at London Bridge, April 8th, 1868. H. M.
High water at Glasgow, April 8th, 2 30 p.m.
Correction for London Bridge, -j- 30
High water at London Bridge,. 3 p.m.
Astronomical Seasons of the Year 1868. — Spring begins, or the sun enters Libra, March 20, 7 h.
4-? m. A.M. ; .summer begins, or the sun enters Cancer, June 21, 4 h. 9 m. a.m. ; autumn begins, or the sun
enters Libra, Sept. 22, 6 h. 32 m. p.m.; winter begins, or the sun enters Capricornus, Dec. 21, h. 28 m. p.m.
June 1st, 1868, the sun's longitude is 71° 12' 20"; and the obliquity of the ecliptic 23° 27' 14"; re-
quired the sun's declination at noon.
To the log. sine of the sun's longitude at noon, 71° 12' 20" 9 976203
Add the log. sine of the obliquity of ecliptic, 23° 27' 14" 9-.599896
To the sine of the snn's declination, 22° 8' 6"
Required the time of rising and setting of the sun at Glasgow, Mav 10, li
long. 4° 16' W.
9-576099
i, in lat. 55° 65' N., and
The approximate time of the rising and setting is :
Rising, 4 h. 7 m.
Longitude of Glasgow, -\- 17
Setting 7 h. 53 m.
Longitude of Glasgow -j- 17
24
8 10
The sun's declination reduced to these times is 17° 41' and 17° 51', and the polar distances are 72° 19'
and 72° 9' — the horizontal refraction less the sun's parallax. Hence the following computation: —
Zenith distance, 90° 33' 90° 33'
Polar distance, 72 19 co-secant 0-021021 72 09 co-secant 0-021426
Co-latitude, 34 08 co-secant 0250944 34 08 co-secant 0-250944
Half sine,.
Equation of time,...
3 59 13
Longitude in time,... -|- 17
Time of rising, 4 16
97

]9(i
50
98
30
siTie 9-995-203
98
25
sine 9-995297
7
67
sine 9-140S60
7
52
sine 9-1.56303
2)19-408018
2)19403970
sine 9-701009
CO
-sine 9-701985
M.
s.
H. m. s.
3

7 58
3
47
Equation of time,.
.. — 3 49
7 64 11
Longitude in time,.. -}- 17
Time of setting, 8 11
JAMES YUILLE,
Teacher of Mathematics, Navigation, and Nautical Astronomy.