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EXPLANATION OF EXAMPLE 14.

On page 118 of the Nautical Almanac, January 23rd, the moon passes the meridian at 0h 22m after noon and would be expressed as 230 00h 22m, from which subtract the correction 16m for longitude 8 hours east, which gives the moon's upper transit at Cape Lambert. To this add the high water interval, 11h 30m, and the result will be the astronomical date and time of high water, 23d 11h 36m, and being less than 12 hours is also civil time P.M.

To the moon's upper transit at Cape Lambert, 23d 00h 06m, add the low water interval, 5h 10m, and the result will be the astronomical date and time of low water, 23d 05h 16m, and being less than 12 hours is also civil time P.M.

From the same page of the Almanac take the moon's lower transit for the 22nd, 22d 11h 52m, and from it subtract the correction 16m for longitude 8 hours east, which gives the moon's lower transit at Cape Lambert, and to this add the high water interval, 11h 30m, and the result will be the astronomical date and time of high water, 22d 23h 16m. To this add 1 day and subtract 12 hours to convert the astronomical time into civil time the 23rd, ilh 06m A.M.

To the moon's lower transit at Cape Lambert, 22d 11h 36m, add the low water interval, 5h 10m, and the result will be the astronomical date and time of low water, 22d 16h 46m. To this add 1 day and subtract 12 hours to convert the astronomical time into civil time the 23rd, 4h 46m A.M.

14. Example: January 23, 1917. Find the times of high waters and low waters at Cape Lambert, Australia.

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II

06

I Low water, 23rd 2 High water, 23rd 3 Low water, 23rd 4 High water, 23rd

A. M.

P. M.

5 II

16 36

P. M.

BY UPPER TRANSIT.

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Moon's upper transit 23rd N. A.
Cor. for long. 8h E.
Moon's upper transit Cape Lambert
High water interval
High water (civil time)
14 lunar day
Low water (civil time)
14 lunar day
High water (ast. time)
Add 1 day and sub. 12 hours
High water (civil time)
1/4 lunar day
Low water (civil time)

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1 Low water, 23rd
2 High water, 23rd
3 Low water, 23rd
4 High water, 23rd

4h 57m A. M. II 10 A. M.

5 23 P. M. II 36 P. M.

EXPLANATION OF EXAMPLE 15.

On page 118 of the Nautical Almanac, January 16th, the moon's upper transit is 18h 23m, which shows at once that the moon passes the meridian of Greenwich at 6h 23m A.M. on the 17th, and for that reason the 15th would be the proper date to use, which is 17h 35m past noon of that date, which corresponds to 5h 35m A.M. of the civil date, the 16th. Then the moon's upper transit would be expressed as 15d 17h 35m, from which subtract the correction 18m for longitude 9 hours east, and the result will be the moon's upper transit at Fowler Point, and to this add the high water interval, 11h 50m, which gives the astronomical date and time of high water, 16d 05h 07m, and being less than 12 hours is also civil time P.M. To the moon's upper transit at

Point, 15d

7h 17m, add the low water interval, 9h 35m, which gives the astronomical date and time of low water, 16d 02h 52m, and being less than 12 hours is also civil time P.M.

From the same page of the Almanac take the moon's lower transit for the 15th, 15d 05h 12m, from which subtract the correction 18m for longitude 9 hours east, which gives the moon's lower transit at Fowler Point. To this add the high water interval, ilh 50m, and the result will be the astronomical date and time of high water, 15d 16h 44m. To this add 1 day and subtract 12 hours to convert the astronomical time into civil time the 16th, 4h 44m A.M.

To the moon's lower transit at Fowler Point, 150 04h 54m, add the low water interval, 9h 35m, which gives the astronomical date and time of low water, 15d 14h 29m. To this add 1 day and subtract 12 hours to convert the astronomical time into civil time the 16th, 2h 29m A.M.

15. Example: January 16, 1917. Find the times of high waters and low waters at Fowler Point, Australia.

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i Low water, 16th 2 High water, 16th 3 Low water, 16th 4 High water, 16th

2h 29m A. M. 4 44 A. M. 2 52 P. M. 5 07 P. M.

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