investigation, ascertained and mapped out; so also have the currents of
the atmosphere, so that, now-a-days, by taking advantage of some of
these currents and avoiding others, voyages are performed, not only in
much shorter time, but with much greater precision and certainty. As it
was with ocean currents long ago, so was it with atmospheric.
Navigators merely put to sea, steered as near as possible on their
direct course, and took advantage of such winds as chanced to blow. Now
they know whither to steer in order to meet with such winds and currents
as will convey them in the shortest space of time to the end of their
voyage. The knowledge necessary to this has not been gained by the
gigantic effort of one mind, nor by the accidental collocation of the
results of the investigations of many ordinary minds. But a few
master-minds have succeeded in gathering within their own grasp the
myriad facts collected by thousands of naval men, of all countries, in
their various voyages; and, by a careful comparison and philosophical
investigation of these facts, they have ascertained and systematised
truths which were before unknown, and have constructed wind and current
charts, by the use of which voyages are wonderfully shortened,
commercial enterprises greatly facilitated, and the general good and
comfort of nations materially advanced.

The truth of this has of late been proved by incontestable facts. For
instance, one year particular note was taken of the arrival of all the
vessels at the port of San Francisco, in California; and it was found
that of 124 vessels from the Atlantic coast of the United States, 70
were possessed of Maury's wind and current charts. The average passage
of these 70 vessels, on that long voyage round Cape Horn, was 135 days;
while the average of those that sailed _without_ the charts (that is,
trusted to their own unaided wisdom and experience) was 146 days.
Between England and Australia the average length of the voyage out used,
very recently, to be 124 days. With the aid of these charts it has now
been reduced to 97 days on the average.

The saving to commerce thus achieved is much greater than one would
suppose. At the risk of becoming tedious to uninquiring readers, we
will make a brief extract from Hunt's "Merchants' Magazine" of 1854, as
given in a foot-note in Maury's "Physical Geography of the Sea."

"Now, let us make a calculation of the annual saving to the commerce of
the United