16 
THE REV. W. WHEWELL ON THE TIDES OF THE PACIFIC, 
is at Cocos Island and at the Galapagos about eight o’clock, comes to the continent 
at Nicoya and Realejo about 10° and 12° north latitude at about three quarters of an 
hour later ; while the tide is at hours later than this, both to the northward and to 
the southward. Proceeding first southward, we find the line of XL not far from 
Callao, that of II. near Coquimbo, or Valparaiso, and that of III. and a half, near 
Valdivia ; and further south, we have the line of V. at Chiloe, and of VI. at Cape 
Pillar, whence the wave moves to the eastward round Cape Horn, as already stated. 
Considering these points as fixed, it is easy to interpolate the other cotidal lines along 
this coast. The observed hour at Guayaquil is later than its position would give, a 
result which we should expect, since the tide will occupy some time in travelling up 
the gulf in which Guayaquil is situated. 
Again, proceeding from Nicoya and Realejo to the northward, we find a like 
progression of tide-hours. The line of X. is not far from Acapulco, according to the 
data here collected. But the tide at Acapulco is small, and hence the accuracy of 
the result is doubtful. Perhaps the smallness of the tide is an indication that the 
point of divergence of the tide-wave, which occurs on this part of the American coast, 
is not far from Acapulco. It appears that the line of III. passes near San Bias, and 
also near the Bay of S. Magdalena on the coast of California. At Mazatlan, some- 
what within the Gulf of California, the time is an hour or two later, as we should 
expect. 
When we reach Monterey and S. Francisco, the hour is about VI. according to 
Capt. Beechey’s observations. The more recent ones are too anomalous to proceed 
upon. At Port Bodega, in lat. 38°, we have the VIII. tide line ; and at Nootka 
Sound, Cook’s observations, which give 12*^ 30"™ (whence Greenwich IX**. nearly), are 
confirmed by Capt. Kellet’s observations in the Straits of Fuca, south of Vancouver’s 
Island. The next point is the Russian settlement of New Archangel, in the island of 
Sitka, where the tides exhibit very curious features, as I have already stated, from 
the observations of Admiral Lutke*, and as I find further confirmed by the obser- 
vations of Sir E. Belcher. The line belonging to Sitka appears to be IX. and a 
half. 
From this point, we depend upon Russian observations which are given by Admiral 
Lutke in his “ Notiee.” These enable us to see that the cotidal lines bend, as usual, 
deep into the head of the bay in which is Cook’s river in lat. 60°. The coast here 
trends to the west, and the wave follows it and pursues its course along the chain of 
the Aleutian Isles, where it has been traced by Admiral Lutke and the navigators 
of the Russo-American Company. It appears that the lines of XL, XIL, I., IL, fall 
near this chain ; and that the line of V. is near the coast of Kamtschatka. It is not 
difficult to arrange the cotidal lines so as to conform to these data. 
Admiral Lutke has observed the tides at other places on the Asiatic coast, as far 
north as 65°, but I shall not attempt to arrange them. 
* See Philosophical Transactions, 1840, Part I. p. 107. 
