INTRODUCTION. 
§ 1. The primary object of "The Wind and Current Charts," 
out of which has grown this Treatise on the Physical Creography 
of the Sea, was to collect the experience of every navigator as to 
the winds and currents of the ocean, to discuss his observations 
upon them, and then to present the world with the results on 
charts for the improvement of commerce and navigation. 
II. Accordingly, when this object was made known, and an ap- 
peal was addressed to mariners, there was a flight up into the gar- 
rets, and a ransacking of time-honored sea-chests in all the mari- 
time communities of the country for old log-books and sea journals. 
III. It was supposed that the records therein contained as to 
winds and weather, the sea and its currents, would afford the in- 
formation requisite for such an undertaking. 
IV. By putting down on a chart the tracks of many vessels on 
the same voyage, but at different times, in different years, and 
during all seasons, and by projecting along each track the winds 
and currents daily encountered, it was plain that navigators here- 
after, by consulting this chart, would have for their guide the re- 
sults of the combined experience of all whose tracks were thus 
pointed out. 
Y. Perhaps it might be the first voyage of a young navigator to 
the given port, when his own personal experience of the winds to 
be expected, the currents to be encountered by the way, would it- 
self be blank. If so, there would be the wind and current chart. 
It would spread out before him the tracks of a thousand vessels 
that had preceded him on the same voyage, wherever it might be, 
and that, too, at the same season of the year. Such a chart, it 
was held, would show him not only the tracks of the vessels, but 
the experience also of each master as to the winds and currents by 
the way, the temperature of the ocean, and the variation of the 
