THE REV. W. WHEWELL ON THE 
tion to be very exact, since the inequality has been tabulated by means of the calen- 
dar months, and thus has been referred to the moon’s mean motion in the ecliptic 
instead of being referred to her actual motion in her own orbit. The greatest effect 
is about half a foot in excess and in defect. 
Leith . — Tide observations have been made at Leith Harbour for several years. I 
have examined these for the diurnal inequality, but it does not appear with any great 
steadiness and regularity. Still its existence is very obvious ; and as the determina- 
tion of its epoch is a curious point, I attempted it in the following manner : 
Leith Tides, 1835. 
| Periods of Max. Diurn. 
Ineq. 
Tides after 
S. Transit. 
Middle of 
Max. 
Inequality 
vanishes. 
Moon’s dec. 
vanishes. 
Difference. 
Days. 
Feb. 15 to 25. 
less 
Feb. 20. 
Feb. 27. 
N. 
Feb. 15. 
12 
March 1 to 13. 
greater 
March 7. 
March 13. 
S. 
March 1. 
12 
March 15 to 25. 
less 
March 20. 
March 27. 
N. 
March 15. 
12 
March 28 to April 8. 
greater 
April 3. 
April 1 1 . 
S. 
March 29. 
13 
April 15 to 22. 
less 
April 19. 
April 26. 
N. 
April 11. 
13 
April 29 to May 9. 
greater 
(small) 
May 4. ' 
May 9. 
S. 
April 24. 
15 
May 1 1 to 18. 
less 
May 15. 
May 22. 
N. 
May 9. 
13 
May 22 to June 7. 
greater 
(small) 
May 30. 
June 6. 
S. 
May 21. 
[16] 
June 9 to 14. 
less 
June 12. 
June 17. 
N. 
June 5. 
12 
June 15 to 30. 
irregular 
June 23. 
June 29. 
S. 
June IS. 
[11] 
July 1 to 8. 
less 
(small) 
July 5. 
July 10. 
N. 
July 2. 
[8] 
July 12 to 19. 
greater 
(irreg.) 
July 16. 
July 20. 
S. 
July 15. 
[5] 
July 21 to 27. 
less 
(small) 
July 24. 
August 3. 
N. 
July 30. 
[5] 
August 10 to 17. 
greater 
August 14. 
August 22. 
S. 
August 11. 
11 
Aug. 26 to Sept. 4. 
less 
August 31. 
Sept. 6. 
N. 
August 26. 
10 
September 8 to 18. 
greater 
Sept. 13. 
Sept. 19. 
S. 
Sept. 8. 
11 
September 20 to 30. 
irregular 
Sept. 25. 
Sept. 30. 
N. 
Sept. 22. 
[8] 
October 1 to 11. 
greater 
October 6. 
S. 
October 5. 
