ACROSS THE ISTHMUS OF PANAMA'. 
63 
of the Atlantic at Chagres ; half the rise and fall of spring tides is at Panama 
10.61 feet, and at Chagres 0.58 of a foot ; and assuming half the rise and fall 
above the low water of spring tides to be the respective mean levels, the mean 
height of the Pacific at Panama is 3.52 feet higher than that of the Atlantic 
at Chagres*. 
Second. — At high water, the time of which is nearly the same on both sides 
the Isthmus, the Pacific is raised at mean tides 10.61 feet, and the Atlantic 
0.58 of a foot, above their respective mean levels ; the Pacific is therefore the 
highest at such times by (10.61—0.58+3.52=) 13.55 feet. 
Third. — At low water, both seas are the same quantities below their re- 
spective mean levels ; therefore at such times the Pacific is lower than the 
Atlantic by (10.61 — 0.58—3.52=) 6.51 feet. 
In every twelve hours therefore, and commencing with high tides, the level 
of the Pacific is first several feet higher than that of the Atlantic ; it becomes 
then of the same height, and at low tide is several feet lower : again, as the tide 
rises the two seas are of one height, and finally at high tide the Pacific is again 
the same number of feet above the Atlantic as at first. 
Almost every person who visits Panama from the Atlantic side is disposed to 
think that the country rises from the Atlantic to the Pacific. The ascent of 
the river Chagres, particularly when swollen by rains and its current rendered 
more than usually rapid, is very toilsome ; and on reaching Cruces after a four or 
five days tedious journey, a traveller is impressed with the persuasion that he has 
gained a considerable elevation above the sea that he has quitted : this im- 
pression is not diminished by the journey to Panama, which is mostly through 
rough and rugged passes, continually ascending and descending ; and when, 
on arriving in the savannahs, a few miles from Panama, the city is beheld for 
the first time with its conspicuous cathedral, the general exclamation is, “I 
thought Panama had been near the level of the sea.” Such is actually its 
situation ; but as the valley from which it is first seen is several feet below the 
level of the sea, the first and strong impression produced, is that the city stands 
upon an eminence. 
* The author is aware that there are different opinions with regard to what is the mean level of the 
ocean; the assumption in the text is conformable to his own opinion, but as the data are given from 
which the conclusions are drawn, every person is furnished with the means of making his own deductions. 
