The night was delightful. Not a single cloud obscured the sky, and the ship, with all sails swelled by a fair wind, ploughed the dark waves, leaving a glittering track behind. We were now on the ocean! Below, blue, foam-crested billows; above, the sky studded with stars;—below, the wide desert of the sea; above, the infallible guides to lead us safely through it.
We awoke to new activity on that great element, which conceals so many charms and so many hardships, where the continued alternations of hope and fear, of enjoyment and privation—where weariness and disappointment, and yet again the new strength imparted by returning success—so excitingly animate, and so gloriously manifest the innate power of the human mind.
Life on board, the various excitements at sea, the different countries and people seen during a voyage, all tend to arouse feelings and sensations which are reserved for the mariner alone, and which render his life, if he knows how to use it properly, happy and most enviable. At sea the mental and physical eye gains strength, man there seeks to unravel Nature in all her phases, and to know and to admire more thoroughly her works. The seaman owes his energy, his straightforwardness, and his piety, to a life spent in the midst of nature, to his direct intercourse with creation. Between him and the Sovereign of the Universe there is, as it were, no mediator—he lives and labours uninterruptedly on the steps of the throne of his Creator and Preserver. In this great temple he directs to Him alone his complaints, his thanks, and his prayers. At sea he learns law and order from Nature herself in her constantly-recurring functions; here he admires the omnipotence and goodness of God in the sunrise after a stormy night, and in the brightness of the moon that lights up his path; here he learns by his actual experience the truth of that maxim of life, that "God only helps him who helps himself."
The wind, hitherto easterly, chopped round to the North-east, which, according to Maury's excellent directions and charts, may be considered as a trade wind, and in this season might be called so. In fact, the trade winds are produced by a current of air, which is directed towards the Equator, and only in consequence of the earth's motion round its axis acquires a north-easterly direction to the north of the equator, and a south-easterly to the south of it. But the trade winds become perceptible at a certain distance from the equator, or rather from the hottest zone of the earth's surface; and it is clear, that when the zone assumes a greater breadth, the boundary of the trade winds is extended further towards the poles, as the position of this zone and its heat obtained from the sun are the causes of these phenomena.
This is exactly the case in these waters; Africa, with its sandy deserts, presents a broader zone of the greatest heat than is possible on the sea, and the trade winds, accordingly, reach further towards the north. Its direction, however, cannot always be north-easterly, and depends necessarily on the direction of the northern boundaries of this zone of greatest heat. Accordingly, we at first had a more northerly wind, which in our progress towards Madeira became much more easterly. The weather continued on the whole beautiful, the sea was calm, and only the increased length of the waves showed the greater expanse of water we were now navigating.
We overtook some other ships, which were sailing towards the west. As we saw nothing of the Caroline, we concluded that she was considerably ahead. The current, which near Gibraltar has a westerly direction, tending towards the Mediterranean, loses its power at a distance from the land, and half-way to Madeira it changes its direction in such a way that the ship is carried imperceptibly southwards, though only a few miles a-day. This current is a lateral branch of the great Gulf Stream, which from the Gulf of Mexico is directed towards England, but about the latitude of New York sends off a branch in a south-easterly direction, which passes round Madeira, and, near the Canaries, takes a parallel direction with the coast of Africa and forms the commencement of the Guinea current. The temperature of the sea water, which in the midst of this current is generally rather higher than that of the air, indicates to the mariner that he is in the Stream, and he must take care that his ship is not carried more to the south out of its course than he wishes. This shows clearly of what importance ocean-currents are to navigation; and it becomes evident that it is the duty of the scientific navigator not only to find out their direction and strength, but to use all means at his command, in order to ascertain their general movement in given districts of ocean.
For this latter purpose, it is customary (as often as circumstances seem to render it advisable) to throw overboard, and commit to the mercy of these currents, a well-corked empty bottle, in which has been deposited a card with the name and position of the ship. The bottle thus prepared, and made conspicuous by a covering of white linen cloth, or some such material, wanders hither and thither with the current, until it is picked up by some other ship, or is stranded anywhere on terra firma. The fact of such a bottle having been picked up is usually published, together with the particulars enclosed, by means of which it is obvious that an estimate can be formed of the average strength and direction of the current.
At 1 p. m. each afternoon, it was our custom to despatch one of these ocean-posts, under given conditions; but only rarely did we afterwards receive any information with respect to them. In each bottle was placed a card with the following particulars, written in German, English, French, Italian, and Spanish:—
"H.I.M. frigate, Novara, such and such a day of the week and month, hour at which thrown overboard, Longitude from Greenwich, Latitude. Whoever finds this bottle, which is about being thrown overboard well-corked and in good order, is requested to forward for publication, to the nearest spot at which there is a newspaper, the day, hour, latitude and longitude, in which the bottle has been found, together with the particulars of a similar nature already enclosed."
On the 7th June, towards evening, we were not more than 55 nautical miles distant from the E. point of Madeira, and as the wind was favourable and pretty fresh, it became necessary to shorten sail, so as to reach the anchorage by daybreak.