300 
THE REV. W. WHEWELL ON TIDE OBSERVATIONS 
promontories under certain circumstances. Thus at the south-east point of Ireland, 
(at Arklow, Glynn, and Cahore,) the greatest range is not more than three feet, while 
at a little distance along the coast each way it becomes twelve or thirteen feet : and 
this small amount of the tide on one side of the channel is the more remarkable, 
because it is just opposite the enormous range which occurs in the Bristol Channel. 
In order to exhibit the succession of facts of this kind, I have drawn out Table X., 
in which the greatest and least range at each place of observation in June 1834 and 
1835 are recorded. The agreement of the two years with one another in the cases in 
which observations have been made in both, shows that these observations are en- 
titled to considerable confidence. It may be observed, moreover, that the formulae 
which have been obtained from the best discussions of tide observations do not lead 
us to expect a complete coincidence of the range in the two years. By the Liverpool 
tables it results (from the corrections for lunar declination and parallax) that the 
highest high water in June 1835 would be three feet one inch above the mean high 
water, while in June 1834 the greatest high water would only be two feet above the 
mean ; and thus the greatest range at Liverpool would be two feet two inches more 
in June 1835 than in June 1834. It will be found that in our table the range of the 
tide is in almost all cases greater in 1835 than in 1834 by a quantity different accord- 
ing to the range itself. 
21. I have also endeavoured in another manner to represent to the eye the course 
followed by the range of the tide. In a Map of the British Isles and the German 
Ocean I have drawn lines parallel to the coast, and expressing, by their number, the 
range of the tide ; as many lines being drawn as there are yards in that range. An 
inspection of this map will make apparent several curious circumstances in the change 
of magnitude which the tide undergoes in its progress. 
By reference either to the table or to the map, it will be seen that the range, which 
is 16 feet at the Scilly Isles, becomes 13 and 12 feet on the coast of Devonshire and 
Dorsetshire, and retains this value, with no great change, (proceeding outside the Isle 
of Wight,) to Selsey : it then increases, so that at Brighton the range is 18 or 19 feet, 
and at Eastbourne 21, which it is also at Dungeness, and not much less at Dover. 
At Dunkirk it is 16 feet French, and on the coast of Belgium it is about 4*5 French 
metres, or 15 feet. But in going along the coast of Holland eastward, it diminishes 
from 4 Dutch ells, its value near Flushing, to 23 ells at Ameland. On the coast of 
Denmark this diminution goes on : the tide is 10 Danish feet at the mouth of the 
Elbe ; but in going north it becomes 5 '6 feet at the point called Bleavand’s Huk, or 
the Horn ; 27 feet at Nyminde Gab ; and only 1*5 foot at Agger, in the inbend of 
the Skaggerrack, which leads to the Baltic. In this neighbourhood we may conceive 
the tides to vanish, and hence I have here placed a pole or centre about which the 
tide-wave revolves, as I have already explained. When we pass this point, and ad- 
vance northwards along the coast of Norway, the tide again assumes a considerable 
magnitude. At Tananger it is only 1 foot 9 inches English ; at Skeudesnaes 2 feet 
