INTRODUCTION. 
vii 
the flight and length of the arrows designated the velocity and set 
of the currents. 
XI. Thus the eye was successfully addressed ; for, by a mere 
glance at the chart, the navigator saw in a moment from what 
quarter he might expect to find the wind in any part of the sea to 
prevail for any month ; and he thus had to guide him across the 
pathless ocean, not theory or conjecture, nor the faint glimmerings 
of any one man's experience, hut the entire blaze and full flood of 
light which the observations of all the navigators that had preceded 
him could shed. 
XII. Thus, while the young ship-master, with these charts be- 
fore him, would be immediately lifted up and placed on a footing 
with the oldest sea-captains in this respect, the aged might see in 
these charts also the voyages made in their young days spread out 
before them. There, on the chart, was the ship's name, her track, 
the year ; and, by the color and fashion of the line (§ IX.), the 
month might be told. There, on that day, in that latitude and 
longitude, these charts would remind the old sailor that he had en- 
countered a terrible gale of wind ; there, that he had been beset 
with calms ; how here, with fair winds and a smooth sea, he had 
made a glorious run. Here, he had first encountered the trades ; 
and there, lost them. At this place, he had met with a " hawsing 
current." Here, the winds were squally with rain ; and there, it 
was he had been beset with fogs ; here, with thunder-storms. All 
this was seen on paper, and so represented as to recall the reality 
vividly to mind. 
XIII. Such a chart could not fail to commend itself to intelli- 
gent ship-masters, and such a chart was constructed for them. 
They took it to sea, they tried it. and to their surprise and delight 
they found that, with the knowledge it afforded, the remote corners 
of the earth were brought closer together, in some instances, by 
many days' sail. The passage hence to the equator alone was 
shortened ten days. Before the commencement of this undertak- 
ing, the average passage to California was 183 days ; but with 
these charts for their guide, navigators have reduced that average, 
and brought it down to 135 days. 
XIV. Between England and Australia, the average time going, 
without these charts, is ascertained to be 124 days, and coming. 
