Os the morning of the 30th April, 1859, one of the most disastrous wrecks on record occurred on the Blackwater Bank, in the Irish Channel, by which melancholy event no less than 385 persons perished.

The American clipper ship Pomona, of 1800 tons burden, sailed from Liverpool on the morning of the 27th of April, for New York, having on board 400 emigrants and passengers, besides the officers and crew, 44 in number.

Embarked in a splendid ship, with a fair breeze, and the prospect of a speedy passage to the place of their destination, most of those on board were in high spirits, little apprehensive of the fearful calamity that was about to befal them. Scarcely, however, had all retired to rest, after a day of pleasing anticipations, than they were awoke to life by the ominous cry—" The ship on shore." But too soon was the terrible reality of their situation made apparent by the seas furiously breaking over them—by the violent shocks which started every timber and plank in the ship, as she was lifted by the waves and dashed again on the ground—by the cries and wailings of the fear-stricken and helpless multitude —and by all the other fearful accompaniments of a shipwreck.

It was shortly ascertained that the ship was aground on the Blackwater Bank, off the Wexford coast, the captain having mistaken the new floating Blackwater light for the Tuskar light, and having, in consequence, ordered- a wrong course to be steered.

It is painful to contemplate the awful state of suspense in which the remaining hours of darkness were passed through by that large number of our hapless fellow-creatures, and the terrible feeling of despair which must have overpowered them, when at break of day they perceived their long distance from the shore, and the slight chance, if any, that could exist of their receiving succour from it.

For twelve long hours after striking the ground their ship held together beneath them, during which interval the usual gradations of suffering and of unavailing efforts were passed through. The pumps were unceasingly worked without being able to subdue the rising flood; the boats were lowered or hoisted out only to be, one after the other, destroyed or upset, with the exception of two in which the few survivors ultimately escaped; the masts were cut away, but all was of no avail; the unequal contest was soon to end; the brave ship and the bravest of her crew were alike impotent to withstand the fury of the storm, and after twelve long hours of exertion and endurance, all was over; the ship and her precious freight had gone down together into the abyss: the last prayer was said; the last shriek was silenced; the last struggle had ceased, and all were enshrouded in a common grave! To ourselves, who have been mercifully preserved from such dangers, the practical questions as usual suggest themselves:— Could anything more have been done than was done to prevent the catastrophe ?—Can any measures be taken to lessen the risks of such wholesale destruction of life in future ? The first cause of the fatal accident, a cause which has been but too fruitful of loss of life in past times, appears to have been the mistaking one light for another. It was by such a mistake that the celebrated wreck of the steamship Great Britain took place some years since, in Dundrum Bay. And many another noble ship has been lost from the same description of error. As in this instance, so also in numberless others, these fatal mistakes are made by ships which have sailed but a few hours out of English ports, to whom, it might be supposed, the lights of our own coast by night, and its landmarks by day, would indicate their course as plainly as do the familiar wayside objects and the cross-road sign-post point out the way to the traveller on the land. That the very warning-light intended to save, may, despite every precaution and great experience, prove the source of destruction, is strikingly illustrated by this wreck, for it is not many months since the Blackwater floating light was first established with the precise object of warning vessels from those fatal banks. Yet there can be little doubt that had there been no such light, the captain of the Pomona would have continued his original course, and would have prosecuted his voyage in safety.

Of what vital importance therefore is it, that all lighthouses contiguous to, or within long distances of each other, should be of such distinctive and different characters as to make the confounding one with another almost impossible, or at least improbable! We do not mean to say that such is not the case as regards the lights now in question, but we do say that, as regards these and all other lights, the authorities who are responsible for them should devote the most serious consideration to the subject, and that if theory suggests, or experience proves, that any specific lights are liable to be mistaken for others,'no trouble and no expense should be spared to remove that liability.

Perhaps the only modes by which lights can be diversified are those already in use, namely, change of colour, and changes of appearance, by being fixed, t. e. uniform and permanent, or by having their light concealed at intervals, as in the revolving and flashing lights. On account of the comparatively short distances from which coloured lights are visible, especially in thick weather, the most common mode of distinc- tion is by partial concealment, but even that is a fallible plan, as when seen at a long distance, or if it be a low light, as in a floating-vessel, a fixed light may, through being obscured by intervening waves, have the appearance of being intermittent. Such a cause may have misled the captain in the present instance, as the Tuskar light is an intermittent one, whilst the floating Blackwater light is fixed. In most cases of doubt from such a cause, perhaps the master of a ship could not do better than run directly for the light itself, until near enough to feel assured of its character and identity.

Some years ago a proposition was made to the Trinity Board, that a system of alternate colours should be adopted, that is to say, that the lighthouses around our coasts should alternate in colour: thus, for instance, commencing with a fixed bright light, that the next should be a red light, the next to that a green one, the next following a violet, and then a bright light again, and so on in the same succession. Thus every fourth light only corresponding, the distance between similar lights would be so much increased as to make it impossible that the one should be mistaken for the other. The objection to this plan was, probably, that the coloured lights are not visible at a sufficient distance.

We think, nevertheless, that the idea was an excellent one, and that it might be so far adopted with advantage, as that the alternate colours should be used in combination with a bright light at intervals in each case, so that every fourth light should be a fixed bright light, the next following to be a revolving or flashing bright light, with intermittent coloured rays, to be followed again by a revolving bright light of different intervals, and with the intermittent rays of a different colour from the preceding. These double - coloured lights a long distances would then have the appearance of bright revolving lights, visible at different intervals, by which interval each would in general be known, whilst a nearer approach would bring to view its coloured rays, and remove all uncertainty as to its identity, or make assurance doubly sure.

Another cause of loss of life in this case, was the destruction of most of the ship's boats; and, indeed, the inadequate number of them, for if all of them had been safely lowered and filled with passengers, they could not have taken in move than one-third of those on board the ship, for we learn there were but seven boats when she left Liverpool.

As we pointed out in the case of the steamship Austria not long since, so again in the case of the Pomona we must point out that if the law afforded to emigrants and other passengers the protection which it ought to do, by the enforcement of a sufficient and suitable supply of boats, much of this sad waste of human life might have been spared. True, two of the boats were washed from the davits by the sea; three of them were stove or upset on being lowered into the water; and of the two which left the ship, one was upset in landing through the surf. But if the boats had been twenty in number, which they ought to have been, instead of seven only; if they had all been life-boats—real life-boats, not sham life-boats, which the generality of ship's lifeboats are—but if they had been WHITE'S life-boats, or BERTHON'S collapsible life-boats, or such life-boats as those adopted by the NATIONAL LIFE-BOAT INSTITUTION, they not only would not have swamped if stove in, but might have been safely filled with passengers afterwards, and have taken them to the shore; and if they had been of the lastnamed class, and had been upset in lowering, they would have righted again instantly after. If each boat had been fitted with CLIFFORD'S lowering apparatus, its chance of being safely lowered, with its complement of passengers, without injury, and without upsetting, would have been infinitely increased.

And if each boat had had a bow.-rope, of sufficient length and strength secured to the ship, which should always be the case, had she been upset, she would not have gone adrift, but have remained by the ship, with the chance of being righted, and of still being available to save life.

Under such circumstances, it may be fairly presumed that many boats full of passengers would have safely left the Pomona, and even if some of them should have been upset in landing through the surf, which, from the ignorance of merchant-seamen of the proper management of boats in a surf, they might have been, yet even then those on board them would have had a greater chance of being saved by aid from the shore than by going down with the ship in deep water.

Once more, then, we exclaim against the injustice, the national moral turpitude, and especially against the supineness of the governing authorities, who have charge of our Mercantile Marine, and, above all, of our Emigration department of it, which affords no better protection to the lives of our fellow countrymen, which, in the manner above pointed out, might so readily be done.

Lastly, another cause of loss of life in this deplorable case appears to us to have arisen from an error in judgment in the captain, by letting go his anchor after the ship had drifted over the bank, and got again into deep water. As shown by the charts, she could not have been more than 2£ miles from the shore, when off the bank, to which also she must have drifted considerably nearer before the anchor was let go, as some time was expended in clearing it away, and as it is stated that the breaking of the surf op the beach was distinctly heard by those on board: as the ship did not go down until about half-an-hour after the anchor was let go, it is probable that she floated for at least an hour after drifting off the bank.

We may therefore conclude that there was ample time for her to have been run on shore, especially if a sail could have been set on the mizenmast, which was still left standing. As soon", therefore, as it was found that the water was gaming on the pumps, it must have been evident that the ship would founder, and that the further she was from the shore at the moment of the final catastrophe, the less chance there must be of any of her inmates reaching it; for even if no boat could, on her first striking, have reached her from the shore, or the mortar or rocket apparatus have been the means of effecting a communication with it, the ship might have held together until the tide had left her.

As it happened, although of course unknown to the captain, the life-boat of the NATIONAL LITE - BOAT INSTITUTION stationed at Cahore, two miles distant, made several attempts to proceed to the wreck, but unfortunately she was as often beaten back again by the sea. If, however, she had succeeded in getting out, all that she could have done would have been to take off some 30 persons, and left the remainder to perish, as the ship would have foundered before she could return to it. On the contrary, had the vessel been drive on shore, she would probably have made the water so much smoother under her lee, that the life-boat might have been more readily launched, and have passed to and fro between the ship and the shore until all on board were saved.

We do not, however, desire to cast any reproach on the captain of the ship, who is said to have shown much coolness, presence of mind, and courage on the trying occasion, and he' no doubt acted to the best of his judgment. All speculation, indeed, as to the correctness of his judgment, is now useless.

Whether correct or not, it was in this instance of no avail; that which was to be has come to pass; it is now irrevocable: and we only state our opinion respecting it for the consideration of masters of ships who may chance hereafter to be placed in similar circumstances.