"Beside the Moldau's rushing stream,
With the wan moon overhead,
There stood, as in an awful dream,
The army of the dead."

Longfellow.

Most of our readers will understand what was meant by Mary Pratt's "inclination of the earth's axis to the plane of its orbit;" but as there may be a few who do not, and as the consequences of this great physical fact are materially connected with the succeeding events of the narrative, we propose to give such a homely explanation of the phenomenon as we humbly trust will render it clear to the most clouded mind. The orbit of the earth is the path which it follows in space in its annual revolution around the sun. To a planet there is no up or down, except as ascent and descent are estimated from and towards itself. In all other respects it floats in vacuum, or what is so nearly so as to be thus termed. Now, let the uninstructed reader imagine a large circular table, with a light on its surface, and near to its centre. The light shall represent the sun, the outer edge of the circle of the table the earth's orbit, and its surface the plane of that orbit. In nature there is no such thing as a plane at all, the space within the orbit being vacant; but the surface of the table gives a distinct notion of the general position of the earth as it travels round the sun. It is scarcely necessary to say that the axis of the earth is an imaginary line drawn through the planet, from one pole to the other; the name being derived from the supposition that our daily revolution is made on this axis.

Now, the first thing that the student is to fix in his mind, in order to comprehend the phenomenon of the seasons, is the leading fact that the earth does not change its attitude in space, if we may so express it, when it changes its position. If the axis were perpendicular to the plane of the orbit, this circumstance would not affect the temperature, as the simplest experiment will show. Putting the equator of a globe on the outer edge of the table, and holding it perfectly upright, causing it to turn on its axis as it passes round the circle, it would be found that the light from the centre of the table would illumine just one half of the globe, at all times and in all positions, cutting the two poles. Did this movement correspond with that of nature, the days and nights would be always of the same length, and there would be no changes of the seasons, the warmest weather being nearest to the equator, and the cold increasing as the poles were approached. No where, however, would the cold be so intense as it now is, nor would the heat be as great as at present, except at or quite near to the equator. The first fact would be owing to the regular return of the sun, once in twenty-four hours; the last to the oblique manner in which its rays struck this orb, in all places but near its centre.

But the globe ought not to be made to move around the table with its axis perpendicular to its surface, or to the "plane of the earth's orbit." In point of fact, the earth is inclined to this plane, and the globe should be placed at a corresponding inclination. Let the globe be brought to the edge of the table, at its south side, and with its upper or north pole inclining to the sun, and then commence the circuit, taking care always to keep this north pole of the globe pointing in the same direction, or to keep the globe itself in what we have termed a fixed attitude. As one half of the globe must always be in light, and the other half in darkness, this inclination from the perpendicular will bring the circle of light some distance beyond the north pole, when the globe is due-south from the light, and will leave an equal space around the opposite pole without any light at all, or any light directly received. Now it is that what we have termed the fixed attitude of the globe begins to tell. If the north pole inclined towards the orbit facing the rim of the table, the light would still cut the poles, the days and nights would still be equal, and there would be no changes in the seasons, though there would be a rival revolution of the globe, by causing it to turn once a year, shifting the poles end for end. The inclination being to the surface of the table, or to the plane of the orbit, the phenomena that are known to exist are a consequence. Thus it is, that the change in the seasons is as much owing to the fixed attitude of the earth in space, as we have chosen to term its polar directions, as to the inclination of its axis. Neither would produce the phenomena without the assistance of the other, as our experiment with the table will show.

Place, then, the globe at the south side of the rim of the table, with its axis inclining towards its surface, and its poles always pointing in the same general direction, not following the circuit of the orbit, and set it in motion towards the east, revolving rapidly on its axis as it moves. While directly south of the light, it would be found that the north pole would be illuminated, while no revolution on the axis would bring the south pole within the circle of the light. This is when a line drawn from the axis of the globe would cut the lamp, were the inclination brought as low as the surface of the table. Next set the globe in motion, following the rim of the table, and proceeding to the east or right hand, keeping its axis always looking in the same general direction, or in an attitude that would be parallel to a north and south line drawn through the sun, were the inclination as low as the surface of the table. This movement would be, in one sense, sideways, the circle of light gradually lessening around the north pole, and extending towards the south, as the globe proceeded east and north, diminishing the length of the days in the northern hemisphere, and increasing them in the southern. When at east, the most direct rays of the light would fall on the equator, and the light would cut the two poles, rendering the days and nights equal. As the globe moved north, the circle of light would be found to increase around the south pole, while none at all touched the north. When on the north side of the table, the northern pole of the globe would incline so far from the sun as to leave a space around it in shadow that would be of precisely the same size as had been the space of light when it was placed on the opposite side of the table. Going round the circle west, the same phenomena would be seen, until coming directly south of the lamp, the north pole would again come into light altogether, and the south equally into shadow.

Owing to this very simple but very wonderful provision of divine power and wisdom, this earth enjoys the relief of the changes in the seasons, as well as the variations in the length of the days. For one half of the year, or from equinox to equinox, from the time when the globe is at a due-west point of the table until it reaches the east, the north pole would always receive the light, in a circle around it, that would gradually increase and diminish; and for the other half, the same would be true of the other hemisphere. Of course there is a precise point on the earth where this polar illumination ceases. The shape of the illuminated part is circular; and placing the point of a pencil on the globe at the extremest spot on the circle, holding it there while the globe is turned on its axis, the lines made would just include the portions of the earth around the globe that thus receives the rays of the sun at midsummer. These lines compose what are termed the arctic and antarctic circles, with the last of which our legend has now a most serious connection. After all, we are by no means certain that we have made our meaning as obvious as we could wish, it being very difficult to explain phenomena of this nature clearly, without actually experimenting.

It is usual to say that there are six months day and six months night in the polar basins. This is true, literally, at the poles only; but, approximatively, it is true as a whole. We apprehend that few persons--none, perhaps, but those who are in habits of study--form correct notions of the extent of what may be termed the icy seas. As the polar circles are in 23° 28, a line drawn through the south pole, for instance, commencing on one side of the earth at the antarctic circle, and extending to the other, would traverse a distance materially exceeding that between New York and Lisbon. This would make those frozen regions cover a portion of this globe that is almost as large as the whole of the Atlantic Ocean, as far south as the equator. Any one can imagine what must be the influence of frost over so vast a surface, in reproducing itself, since the presence of ice-bergs is thought to affect our climate, when many of them drift far south in summer. As power produces power, riches wealth, so does cold produce cold. Fill, then, in a certain degree, a space as large as the North Atlantic Ocean with ice in all its varieties, fixed, mountain and field, berg and floe, and one may get a tolerably accurate notion of the severity of its winters, when the sun is scarce seen above the horizon at all, and then only to shed its rays so obliquely as to be little better than a chill-looking orb of light, placed in the heavens simply to divide the day from the night.

This, then, was the region that Roswell Gardiner was so very anxious to leave; the winter he so much dreaded. Mary Pratt was before him, to say nothing of his duty to the deacon; while behind him was the vast polar ocean just described, about to be veiled in the freezing obscurity of its long and gloomy twilight, if not of absolute night. No wonder, therefore, that when he trimmed his sails that evening, to beat out of the great bay, that it was done with the earnestness with which we all perform duties of the highest import, when they are known to affect our well-being, visibly and directly.

"Keep her a good full, Mr. Hazard," said Roswell, as he was leaving the deck, to take the first sleep in which he had indulged for four-and-twenty hours; "and let her go through the water. We are behind our time, and must keep in motion. Give me a call if anything like ice appears in a serious way."

Hazard "ay-ay'd" this order, as usual, buttoned his pee-jacket tighter than ever, and saw his young superior--the transcendental delicacy of the day is causing the difference in rank to be termed "senior and junior"--but Hazard saw his superior go below, with a feeling allied to envy, so heavy were his eye-lids with the want of rest. Stimson was in the first-mate's watch, and the latter approached that old sea-dog with a wish to keep himself awake by conversing.

"You seem as wide awake, king Stephen," the mate remarked, "as if you never felt drowsy!"

"This is not a part of the world for hammocks and berths, Mr. Hazard," was the reply. "I can get along, and must get along, with a quarter part of the sleep in these seas as would sarve me in a low latitude."

"And I feel as if I wanted all I can get. Them fellows look up well into our wake, Stephen."

"They do indeed, sir, and they ought to do it; for we have been longer than is for our good, in their'n."

"Well, now we have got a fresh start, I hope we may make a clear run of it. I saw no ice worth speaking of, to the nor'ard here, before we made sail."

"Because you see'd none, Mr. Hazard; is no proof there is none. Floe-ice can't be seen at any great distance though its blink may. But, it seems to me, it's all blink in these here seas!"

"There you're quite right, Stephen; for turn which way you will, the horizon has a show of that sort----"

"Starboard"--called out the look-out forward--"keep her away--keep her away--there is ice ahead."

"Ice in here!" exclaimed Hazard, springing forward--"That is more than we bargained for! Where away is your ice, Smith?"

"Off here, sir, on our weather bow--and a mortal big field of it--jist sich a chap as nipp'd the Vineyard Lion, when she first came in to join us. Sich a fellow as that would take the sap out of our bends, as a squeezer takes the juice from a lemon!"

Smith was a carpenter by trade, which was probably the reason why he introduced this figure. Hazard saw the ice with regret; for he had hoped to work the schooner fairly out to sea in his watch; but the field was getting down through the passage in a way that threatened to cut off the exit of the two schooners from the bay. Daggett kept close in his wake, a proof that this experienced navigator in such waters saw no means to turn farther to windward. As the wind was now abeam, both vessels drove rapidly ahead; and in half an hour the northern point of the land they had so lately left came into view close aboard of them. Just then the moon rose, and objects became more clearly visible.

Hazard hailed the Vineyard Lion, and demanded what was to be done. It was possible, by hauling close on a wind, to pass the cape a short distance to windward of it, and seemingly thus clear the floe. Unless this were done, both vessels would be compelled to ware, and run for the southern passage, which would carry them many miles to leeward, and might place them a long distance on the wrong side of the group.

"Is Captain Gar'ner on deck?" asked Daggett, who had now drawn close up on the lee-quarter of his consort, Hazard having brailed his foresail and laid his topsail sharp aback, to enable him to do so--"If he isn't, I'd advise you to give him a call at once."

This was done immediately; and while it was doing, the Vineyard Lion swept past the Oyster Pond schooner. Roswell announced his presence on deck just as the other vessel cleared his bows.

"There's no time to consult, Gar'ner," answered Daggett. "There's our road before us. Go through it we must, or stay where we are until that field-ice gives us a jam down yonder in the crescent. I will lead, and you can follow as soon as your eyes are open."

One glance let Roswell into the secret of his situation. He liked it little, but he did not hesitate.

"Fill the topsail, and haul aft the foresheet," were the quiet orders that proclaimed what he intended to do.

Both vessels stood on. By some secret process, every man on board the two craft became aware of what was going on, and appeared on deck. All hands were not called, nor was there any particular noise to attract attention; but the word had been whispered below that there was a great risk to run. A risk it was, of a verity! It was necessary to stand close along that iron-bound coast where the seals had so lately resorted, for a distance of several miles. The wind would not admit of the schooners steering much more than a cable's length from the rocks for quite a league; after which the shore trended to the southward, and a little sea-room would be gained. But on those rocks the waves were then beating heavily, and their bellowings as they rolled into the cavities were at almost all times terrific. There was some relief, however, in the knowledge obtained of the shore, by having frequently passed up and down it in the boats. It was known that the water was deep close to the visible rocks, and that there was no danger as long as a vessel could keep off them.

No one spoke. Every eye was strained to discern objects ahead, or was looking astern to trace the expected collision between the floe-ice and the low promontory of the cape. The ear soon gave notice that this meeting had already taken place; for the frightful sound that attended the cracking and rending of the field might have been heard fully a league. Now it was that each schooner did her best! Yards were braced up, sheets flattened, and the helm tended. The close proximity of the rocks on the one side, and the secret presentiment of there being more field-ice on the other, kept every one wide awake. The two masters, in particular, were all eyes and ears. It was getting to be very cold; and the sort of shelter aloft that goes by the quaint name of "crow's-nest," had been fitted up in each vessel. A mate was now sent into each, to ascertain what might be discovered to windward. Almost at the same instant, these young seamen hailed their respective decks, and gave notice that a wide field was coming in upon them, and must eventually crush them, unless avoided. This startling intelligence reached the two commanders in the very same moment. The emergency demanded decision, and each man acted for himself. Roswell ordered his helm put down, and his schooner tacked. The water was not rough enough to prevent the success of the maneuvre. On the other hand, Daggett kept a rap full, and stood on. Roswell manifested the most judgment and seamanship. He was now far enough from the cape to beat to windward; and, by going nearer to the enemy, he might always run along its southern boundary, profit by any opening, and would be by as much as he could thus gain, to windward of the coast. Daggett had one advantage. By standing on, in the event of a return becoming necessary, he would gain in time. In ten minutes the two schooners were a mile asunder. We shall first follow that, of Roswell Gardiner's, in his attempt to escape.

The first floe, which was ripping and tearing one of its angles into fragments, as it came grinding down on the cape, soon compelled the vessel to tack. Making short reaches, Roswell ere long found himself fully a mile to windward of the rocks, and sufficiently near to the new floe to discern its shape, drift, and general character. Its eastern end had lodged upon the field that first came in, and was adding to the vast momentum with which that enormous floe was pressing down upon the cape. Large as was that first visiter to the bay, this was of at least twice if not of thrice its dimensions. What gave Roswell the most concern was the great distance that this field extended to the westward. He went up into the crow's-nest himself, and, aided by the light of a most brilliant moon, and a sky without a cloud, he could perceive the blink of ice in that direction, as he fancied, for fully two leagues. What was unusual, perhaps, at that early season of the year, these floes did not consist of a vast collection of numberless cakes of ice; but the whole field, so far as could then be ascertained, was firm and united. The nights were now so cold that ice made fast wherever there was water; and it occurred to our young master that, possibly, fragments that had once been separated and broken by the waves, might have become re-united by the agency of the frost. Roswell descended from the crow's-nest half chilled by a cutting wind, though it blew from a warm quarter. Summoning his mates, he asked their advice.

"It seems to me, Captain Gar'ner," Hazard replied, "there's very little choice. Here we are, so far as I can make it out, embayed, and we have only to box about until day-light comes, when some chance may turn up to help us. If so, we must turn it to account; if not, we must make up our minds to winter here."

This was coolly and calmly said; though it was clear enough that Hazard was quite in earnest.

"You forget there may be an open passage to the westward, Mr. Hazard," Roswell rejoined, "and that we may yet pass out to sea by it. Captain Daggett is already out of sight in the western board, and we may do well to stand on after him."

"Ay, ay, sir--I know all that, Captain Gar'ner, and it may be as you say, but when I was aloft, half an hour since, if there wasn't the blink of ice in that direction, quite round to the back of the island, there wasn't the blink of ice nowhere hereabouts. I'm used to the sight of it, and can't well be mistaken."

"There is always ice on that side of the land, Hazard, and you may have seen the blink of the bergs which have hugged the cliffs in that quarter all summer. Still, that is not proving we shall find no outlet. This craft can go through a very small passage, and we must take care and find one in proper time. Wintering here is out of the question. A hundred reasons tell us not to think of such a thing, besides the interests of our owners. We are walking along this floe pretty fast, though I think the vessel is too much by the head; don't it strike you so, Hazard?"

"Lord, sir, it's nothing but the ice that has made, and is making for'ard! Before we got so near the field as to find a better lee, the little lipper that came athwart our bows froze almost as soon as it wet us. I do suppose, sir, there are now several tons of ice on our bows, counting from channel to channel, forward."

On an examination this proved to be true, and the knowledge of the circumstance did not at all contribute to Gardiner's feeling of security. He saw there was no time to be lost, and he crowded sail with a view of forcing the vessel past the dangers if possible, and of getting her into a milder climate. But even a fast-sailing schooner will scarcely equal our wishes under such circumstances. There was no doubt that the Sea Lion's speed was getting to be affected by the manner in which her bows were weighed down by ice, in addition to the discomfort produced by cold, damp, and the presence of a slippery substance on the deck and rigging. Fortunately there was not much spray flying, or matters would have been much worse. As it was, they were bad enough, and very ominous of future evil.

While the Sea Lion of Oyster Pond was running along the margin of the ice in the manner just described, and after the blink to the westward had changed to a visible field, making it very uncertain whether any egress was to be found in that quarter or not, an opening suddenly appeared trending to the northward, and sufficiently wide, as Roswell thought, to enable him to beat through it. Putting his helm down, his schooner came heavily round, and was filled on a course that soon carried her half a mile into this passage. At first, everything seemed propitious, the channel rather opening than otherwise, while the course was such--north-north-west--as enabled the vessel to very long legs on one tack, and that the best. After going about four or five times, however, all these flattering symptoms suddenly changed, by the passage's terminating in a cul de sac. Almost at the same instant the ice closed rapidly in the schooner's wake. An effort was made to run back, but it failed in consequence of an enormous floe's turning on its centre, having met resistance from a field closer in, that was, in its turn, stopped by the rocks. Roswell saw at once that nothing could be done at the moment. He took in all his canvass, as well as the frozen cloth could be handled, got out ice-anchors, and hauled his vessel into a species of cove where there would be the least danger of a nip, should the fields continue to close.

All this time Daggett was as busy as a bee. He rounded the headland, and flattered himself that he was about to slip past all the rocks, and get out into open water, when the vast fields of which the blink had been seen even by those in the other vessel, suddenly stretched themselves across his course in a way that set at defiance all attempts to go any further in that direction. Daggett wore round, and endeavoured to return. This was by no means as easy as it was to go down before the wind, and his bows were also much encumbered with ice; more so, indeed, than those of the other schooner. Once or twice his craft missed stays in consequence of getting so much by the head, and it was deemed necessary to heave-to, and take to the axes. A great deal of extra and cumbrous weight was gotten rid of, but an hour of most precious time was lost.

By the time Daggett was ready to make sail again, he found his return round the headland was entirely cut off, by the field's having come in absolute contact with the rocks!

It was now midnight, and the men on board both vessels required rest. A watch was set in each, and most of the people were permitted to turn in. Of course, proper look-outs were had, but the light of the moon was not sufficiently distinct to render it safe to make any final efforts under its favour. No great alarm was felt, there being nothing unusual in a vessel's being embayed in the ice; and so long as she was not nipped or pressed upon by actual contact the position was thought safe rather than the reverse. It was desirable, moreover, for the schooners to communicate with each other; for some advantage might be known to one of the masters that was concealed by distance from his companion. Without concert, therefore, Roswell and Daggett came to the same general conclusions, and waited patiently.

The day came at last, cold and dreary, though not altogether without the relief of an air that blew from regions far warmer than the ocean over which it was now travelling. Then the two schooners became visible from each other, and Roswell saw the jeopardy of Daggett, and Daggett saw the jeopardy of Roswell. The vessels were little more than a mile apart, but the situation of the Vineyard Lion was much the most critical. She had made fast to the floe, but her support itself was in a steady and most imposing motion. As soon as Roswell saw the manner in which his consort was surrounded, and the very threatening aspect of the danger that pressed upon him, his first impulse was to hasten to him, with a party of his own people, to offer any assistance he could give. After looking at the ice immediately around his own craft, where all seemed to be right, he called over the names of six of his men, ordered them to eat a warm breakfast, and to prepare to accompany him.

In twenty minutes Roswell was leading his little party across the ice, each man carrying an axe, or some other implement that it was supposed might be of use. It was by no means difficult to proceed; for the surface of the floe, one seemingly more than a league in extent, was quite smooth, and the snow on it was crusted to a strength that would have borne a team.

"The water between the ice and the rocks is a much narrower strip than I had thought," said Roswell, to his constant attendant, Stimson. "Here, it does not appear to be a hundred yards in width!"

"Nor is it, sir--whew--this trotting in so cold a climate makes a man puff like a whale blowing--but, Captain Gar'ner, that schooner will be cut in two before we can get to her. Look, sir; the floe has reached the rocks already, quite near her; and it does not stop the drift at all, seemingly."

Roswell made no reply; the state of the Vineyard Lion did appear to be much more critical than he had previously imagined. Until he came nearer to the land, he had formed no notion of the steady power with which the field was setting down on the rocks on which the broken fragments were now creeping like creatures endowed with life. Occasionally, there would be loud disruptions, and the movement of the floe would become more rapid; then, again, a sort of pause would succeed, and for a moment the approaching party felt a gleam of hope. But all expectations of this sort were doomed to be disappointed.

"Look, sir!" exclaimed Stimson--"she went down afore it twenty fathoms at that one set. She must be awful near the rocks, sir!"

All the men now stopped. They knew they were powerless: and intense anxiety rendered them averse to move. Attention appeared to interfere with their walking on the ice; and each held his breath in expectation. They saw that the schooner, then less than a cable's length from them, was close to the rocks; and the next shock, if anything like the last, must overwhelm her. To their astonishment, instead of being nipped, the schooner rose by a stately movement that was not without grandeur, upheld by broken cakes that had got beneath her bottom, and fairly reached the shelf of rocks almost unharmed. Not a man had left her; but there she was, placed on the shore, some twenty feet above the surface of the sea, on rocks worn smooth by the action of the waves! Had the season been propitious, and did the injury stop here, it might have been possible to get the craft into the water again, and still carry her to America.

But the floe was not yet arrested. Cake succeeded cake, one riding over another, until a wall of ice rose along the shore, that Roswell and his companions, with all their activity and courage, had great difficulty in crossing. They succeeded in getting over it, however; but when they reached the unfortunate schooner, she was literally buried. The masts were broken, the sails torn, rigging scattered, and sides stove. The Sea Lion of Martha's Vineyard was a worthless wreck--worthless as to all purposes but that of being converted into materials for a smaller craft, or to be used as fuel.

All this had been done in ten minutes! Then it was that the vast superiority of nature over the resources of man made itself apparent. The people of the two vessels stood aghast with this sad picture of their own insignificance before their eyes. The crew of the wreck, it is true, had escaped without difficulty; the movement having been as slow and steady as it was irresistible. But there they were, in the clothes they had on, with all their effects buried under piles of ice that were already thirty or forty feet in height.

"She looks as if she was built there, Gar'ner!" Daggett coolly observed, as he stood regarding the scene with eyes as intently riveted on the wreck as human organs were ever fixed on any object. "Had a man told me this could happen, I would not have believed him!"

"Had she been a three-decker, this ice would have treated her in the same way. There is a force in such a field that walls of stone could not withstand."

"Captain Gar'ner--Captain Gar'ner," called out Stimson, hastily; "we'd better go back, sir; our own craft is in danger. She is drifting fast in towards the cape, and may reach it afore we can get to her!"

Sure enough, it was so. In one of the changes that are so unaccountable among the ice, the floe had taken a sudden and powerful direction towards the entrance of the Great Bay. It was probably owing to the circumstance that the inner field had forced its way past the cape, and made room for its neighbour to follow. A few of Daggett's people, with Daggett himself, remained to see what might yet be saved from the wreck; but all the rest of the men started for the cape, towards which the Oyster Pond craft was now directly setting. The distance was less than a league; and, as yet, there was not much show on the rocks. By taking an upper shelf, it was possible to make pretty good progress; and such was the manner of Roswell's present march.

It was an extraordinary sight to see the coast along which our party was hastening, just at that moment. As the cakes of ice were broken from the field, they were driven upward by the vast pressure from without, and the whole line of the shore seemed as if alive with creatures that were issuing from the ocean to clamber on the rocks. Roswell had often seen that very coast peopled with seals, as it now appeared to be in activity with fragments of ice, that were writhing, and turning, and rising, one upon another, as if possessed of the vital principle.

In half an hour Roswell and his party reached the house. The schooner was then less than half a mile from the spot, still setting in, along with the outer field, but not nipped. So far from being in danger of such a calamity, the little basin in which she lay had expanded, instead of closing; and it would have been possible to handle a quick-working craft in it, under her canvass. An exit, however, was quite out of the question; there being no sign of any passage to or from that icy dock. There the craft still lay, anchored to the weather-floe, while the portion of her crew which remained on board was as anxiously watching the coast as those who were on the coast watched her. At first, Roswell gave his schooner up; but on closer examination found reason to hope that she might pass the rocks, and enter the inner, rather than the Great, Bay.