Now, here are four important mistakes,--important both in a scientific and in a practical point of view.

For, 1st, Not calms and squalls alone, but occasionally fresh and steady winds, are found between the Trades; 2ndly, The belt called the Variables is by no means equally divided by the equator; neither, 3rdly, is that belt stationary in its position; nor, 4thly, is it uniform in its breadth.

It will thence be easily understood, even by a person who has never quitted one of the midland counties in England, and to whom the ocean is an unseen wonder, that a new-comer to the tropical regions, his head loaded with these false views, will be very apt to mistake his own ignorance for the caprice of Nature, and perhaps call out, as I once heard a man do, in all the agony of impatience caused by a protracted head-wind,--"Now, this is really scandalous usage of the clerk of the weather-office!" The scandal, however, lay not so much with the clerk's usage as with his own limited knowledge; for if, at the very time of his imprecation, instead of abusing the foul wind, and keeping his yards braced sharp up, and making his sails stand like a board, the grumbler had known how to take advantage of it, and had kept away two or three points, set his fore-topmast studding-sail, and flanked across or through the breeze which he had in vain tried to beat against, he might not only have saved his temper, but have made his passage in half the time.
I am not sure that, in the whole range of this extensive subject, there could be picked out an instance more in point to what has just been said, than these interesting phenomena of the Trade-winds.

To sailors of every age and rank, and especially to naval officers, an acquaintance with the laws which regulate these extraordinary aerial currents must be of great importance.

For a commander may be ordered, at a moment's warning, either to carry his own ship, or to lead a squadron, or to guard a convoy, from the northern to the southern hemisphere, or perhaps from the West to the East Indies.