WAVES OF THE ATLANTIC AND GERMAN OCEANS. 25 
In 1842 several observations were made on the waves of the Irish Sea at 
the island of Little Ross, lying off the Bay of Kirkcudbright. Since April 1848 till 
now, continued observations have been made on the Atlantic at the Skerryvore 
and neighbouring rocks, lying off the island of Tyree, Argyllshire. And in 1844 a 
series of similar observations was begun on the German Ocean at the Bell itock. 
It will be seen, that in selecting these localities a varied exposure has been em- 
braced, comprising the comparatively sheltered Irish Sea, the more exposed eastern 
shore of Scotland, and the wild rocks of Skerryvore, which are open to the 
full fury of the Atlantic, the far distant shores of North America being the nearest 
land on the west. 
Referring for more full information to the tables of experiments which are given 
at the end of this paper, it will be sufficient in this place to state generally the 
following, as the results obtained. 
In the Atlantic Ocean, according to the observations made at the Skerryvore 
rocks, the average of results for five of the swmmer months during the years 1843 
and 1844, is 611 Ib. per square foot. The average results for six of the winter 
months (1843 and 1844), is 2086 lb. per square foot, or thrice as great as in the 
summer months. 
The Greatest result yet obtained at Skerryvore was during the heavy westerly 
gale of 29th March 1845, when a pressure of 6083 lb. per square foot was regis- 
tered. The next highest is 5323 Ib. 
In the German Ocean, according to the observations made at the Bell Rock, 
the greatest result yet obtained is 3013 lb. per square foot. 
It thus appears, that the greatest effect of the sea, which has been observed, 
is that of the Atlantic at Skerryvore, which is nearly equal to three tons per 
square foot. 
These experiments, amounting to 267 in number,* and on the Atlantic alone 
extending over 23 months continuously, are not intended to prove any thing far- 
ther than the simple fact, that the sea has been known to exert a force equivalent 
to a pressure of three tons per square foot, however much more. Now, when we 
consider that the hydrostatic pressure due to a wave of 20 feet high, is no more 
than about half a ton on a square foot, we see how much of their force the 
waves owe to their velocity. There can be no doubt, however, that results 
higher than this will be obtained. Were a train of observations made at various 
points of the coast, the result would not only be highly useful in practice, as 
they would by reference to existing marine works shew what sizes of stones and 
proportions of piers were able to resist seas of a given force; but they would 
form an interesting collection of information with regard to the relative forces 
of the waves in our contracted bays and estuaries, as compared with those ob- 
* It was not thought necessary to give all the observations in the table appended to this paper. 
VOL. XVI. PART I, G 
