Increased facility in the extension and application of steam-navigation is expected to arise from the substitution of iron for wood, in the construction of vessels. Hitherto iron steamers have been chiefly confined to river-navigation; but there appears no sufficient reason why their use should be thus limited. For sea-voyages they offer many advantages; they are not half the weight of vessels of equal tonnage constructed of wood; and, consequently, with the same tonnage they will have less draught of water, and therefore less resistance to the propelling power; or, with the same draught of water and the same resistance, they will carry a proportionally heavier cargo. The nature of their material renders them more stiff and unyielding than timber; and they do not suffer that effect which is called hogging, which arises from a slight alteration which takes place in the figure of a timber vessel in rolling, accompanied by an alternate opening and closing of the seams. Iron vessels have the further advantage of being more proof against fracture upon rocks. If a timber vessel strike, a plank is broken, and a chasm opened in her many times greater than the point of rock which produces the concussion. If an iron vessel strike, she will either merely receive a dinge, or be pierced by a hole equal in size to the point of rock which she encounters. Some examples of the strength of iron vessels were given by Mr. Macgregor Laird, in his evidence before the Committee of the Commons on Steam Navigation, among which the following may be mentioned:—An iron vessel, called the Alburkah, in one of their experimental trials got aground, and lay upon her anchor: in a wooden vessel the anchor would probably have pierced her bottom; in this case, however, the bottom was only dinged. An iron vessel, built for the Irish Inland Navigation Company, was being towed across Lough Derg in a gale of wind, when the towing rope broke, and she was driven upon rocks, on which she bumped for a considerable time [Pg483] without any injury. A wooden vessel would in this case have gone to pieces. A further advantage of iron vessels (which in warm climates is deserving of consideration) is their greater coolness and perfect freedom from vermin.
Iron steam-vessels on a very large scale are now in preparation in the ports of Liverpool and Bristol, intended for long sea-voyages. The largest vessel of this description which has yet been projected is stated to be in preparation for the voyage between Bristol and New York, by the company who have established the steam-ship called the Great Western, plying between these places.
Several projects for the extension of steam-navigation to voyages of considerable length have lately been entertained both by the public and by the legislature, and have imparted to every attempt to improve steam-navigation increased interest. A committee of the House of Commons collected evidence and made a report in the last session in favour of an experiment to establish a line of steam-communication between Great Britain and India. Two routes have been suggested by the committee, each being a continuation of the line of Admiralty steam-packets already established to Malta and the Ionian Isles. One of the routes proposed is through Egypt, the Red Sea, and across the Indian Ocean to Bombay, or some of the other presidencies; the other across the north part of Syria to the banks of the Euphrates, by that river to the Persian Gulf, and from thence to Bombay. Each of these routes will be attended with peculiar difficulties, and in both a long sea-voyage will be encountered.
In the route by the Red Sea it is proposed to establish steamers between Malta and Alexandria (eight hundred and sixty miles). A steamer of four hundred tons' burden and one hundred horse-power would perform this voyage, upon an average of all weathers incident to the situation, in from five to six days, consuming ten tons of coal per day. But it is probable that it might be found more advantageous to establish a higher ratio between the power and the tonnage. From Alexandria the transit might be effected by land across the isthmus to Suez—a journey of from four to five days—by caravan and camels; or the transit might be made either [Pg484] by land or water from Alexandria to Cairo, a distance of one hundred and seventy-three miles; and from Cairo to Suez, ninety-three miles, across the desert, in about five days. At Suez would be a station for steamers, and the Red Sea would be traversed in three runs or more. If necessary, stations for coals might be established at Cosseir, Judda, Mocha, and finally at Aden or at Socatra—an island immediately beyond the mouth of the Red Sea, in the Indian Ocean; the run from Suez to Cosseir would be three hundred miles—somewhat more than twice the distance from Liverpool to Dublin. From Cosseir to Judda, four hundred and fifty miles; from Judda to Mocha, five hundred and seventeen miles; and from Mocha to Socatra, six hundred and thirty-two miles. It is evident that all this would, without difficulty, in the most unfavourable weather, fall within the present powers of steam-navigation. If the terminus of the passage be Bombay, the run from Socatra to Bombay will be twelve hundred miles, which would be from six to eight days' steaming. The whole passage from Alexandria to Bombay, allowing three days for delay between Suez and Bombay, would be twenty-six days: the time from Bombay to Malta would therefore be about thirty-three days; and adding fourteen days to this for the transit from Malta to England, we should have a total of forty-seven days from London to Bombay, or about seven weeks.
If the terminus proposed were Calcutta, the course from Socatra would be one thousand two hundred and fifty miles south-east to the Maldives, where a station for coals would be established. This distance would be equal to that from Socatra to Bombay. From the Maldives, a run of four hundred miles would reach the southern point of Ceylon, called the Point de Galle, which is the best harbour (Bombay excepted) in British India: from the Point de Galle, a run of six hundred miles will reach Madras, and from Madras to Calcutta would be a run of about six hundred miles. The voyage from London to Calcutta would be performed in about sixty days.
At a certain season of the year there exists a powerful physical opponent to the transit from India to Suez: from [Pg485] the middle of June until the end of September, the south-west monsoon blows with unabated force across the Indian Ocean, and more particularly between Socatra and Bombay. This wind is so violent as to leave it barely possible for the most powerful steam-packet to make head against it, and the voyage could not be accomplished without serious wear and tear upon the vessels during these months.
The attention of parliament has therefore been directed to another line of communication, not liable to this difficulty: it is proposed to establish a line of steamers from Bombay through the Persian Gulf to the Euphrates.
The run from Bombay to a place called Muscat, on the southern shore of the gulf, would be eight hundred and forty miles in a north-west direction, and therefore not opposed to the south-west monsoon. From Muscat to Bassidore, a point upon the northern coast of the strait at the mouth of the Persian Gulf, would be a run of two hundred and fifty-five miles; from Bassidore to Bushire, another point on the eastern coast of the Persian Gulf, would be a run of three hundred miles; and from Bushire to the mouth of the Euphrates, would be one hundred and twenty miles. It is evident that the longest of these runs would offer no more difficulty than the passage from Malta to Alexandria. From Bussora, near the mouth of the Euphrates, to Bir, a town upon its left bank near Aleppo, would be one thousand one hundred and forty-three miles, throughout which there are no physical obstacles to the river-navigation which may not be overcome. Some difficulties arise from the wild and savage character of the tribes who occupy its banks. It is, however, thought that by proper measures, and securing the co-operation of the pacha of Egypt, any serious obstruction from this cause may be removed. From Bir, by Aleppo, to Scanderoon, a port upon the Mediterranean, opposite Cyprus, is a land-journey, said to be attended with some difficulty, but not of great length; and from Scanderoon to Malta is about the same distance as between the latter place and Alexandria. It is calculated that the time from London to Bombay by the Euphrates—supposing the passage to be successfully [Pg486] established—would be a few days shorter than by Egypt and the Red Sea.
Whichever of these courses may be adopted, it is clear that the difficulties, so far as the powers of the steam engine are concerned, lie in the one case between Socatra and Bombay, or between Socatra and the Maldives, and in the other case between Bombay and Muscat. This, however, has already been encountered and overcome on four several voyages by the Hugh Lindsay steamer from Bombay to Suez: that vessel encountered a still longer run on these several trips, by going, not to Socatra, but to Aden, a point on the coast of Arabia, near the Straits of Babel Mandeb, being a run of one thousand six hundred and forty-one miles, which she performed in ten days and nineteen hours. The same trip has since been repeatedly made by other steamers; and, in the present improved state of steam navigation, no insurmountable obstacles are opposed to their passage.