The introduction of steam-packets upon the open sea was a favourite object with Dodd. lie observes particularly the great importance of their establishment between Dublin and Holyhead, as the intercourse by sailing packets was liable to great delays. They were sometimes, it is stated, more than seventy-six hours at sea, although the distance is only about sixty miles. The use of steam-vessels upon this station was advocated for several years before they were regularly established ; and Dodd had, on behalf of himself and friends, offered to bear the expense of two packets for making the experiment, provided the Post-office authorities would guarantee to him the conveyance of the mails, in the event of those packets fully answering his representations; but his offer was not accepted. It has been shown that some sea-voyages were performed at an earlier date ; but the regular establishment of ocean steam navigation may be considered to have commenced with the Rob Roy, a steamer of about thirty-horse power and ninety tons burden, which commenced running in 1818 between Greenock and Belfast. This vessel was established by Mr. David Napier, who, says Russell, from the year 1818 until about 1830, " effected more for the improvement of steam navigation than any other man." This gentle man must be distinguished from his cousin, Mr. Robert Napier, of Glasgow, who is also honourably known for improvements of the same kind, but of a somewhat later date. David Napier, according to the interesting narrative of the progress of steam navigation in Britain, given by tho above-mentioned writer, ventured at once to establish regular communication between Britain and the neighbouring countries, Ireland and France, by steam-vessels plying even during the stormy months of winter ; though, previous to the time of his improvements, such vessels had scarcely ever ventured to sea except in fine weather. In order to make himself well acquainted with the difficulties to be overcome, he took passage, at the worst season of the year, in one of the sailing vessels which formerly plied between Glasgow and Belfast, and which often required a week to perform a journey that is now done by steam in nine hours. After anxiously watching the effect of the waves when the vessel was tossed iu a storm, and satisfying him self that there was no insuperable difficulty, he retired contentedly to his cabin, leaving the captain of the vessel puzzled at his strange curiosity respecting the effect of rough weather. He subsequently tried experiments upon the best form of hull for getting through the water with the minimum of resistance ; and these led him to adopt a fine wedge-like form for the fore part of his vessels, instead of the round full bow common in those propelled by sails. The Rob Roy, after plying two winters between Greenock and Belfast, was removed from that line, and employed as a packet between Dover and In 1819 he employed the Messrs. Wood to build the Talbot, of one hundred and fifty tons burden, into which he fitted two engines of thirty horse-power each. This fine vessel, the most perfect of her time in all respects, plied between Holyhead and Dublin ; and she was soon followed, on the same line, by another excellent vessel, called the Ivanhoe. In 1821 steam-vessels were regularly established as Post office packets on that important station. They had been intended merely as auxiliaries to the sailing packets ; but they soon superseded them. From the evidence given before the Holyhead Roads Com mittee in 1822, it appears that even then the intercourse between the two countries had been reduced almost to a certainty; and that while, in the year preceding their adoption, exactly one hundred mails arrived in London after the proper time, there were only twenty-two cases of delay in the first nine months in which the steam-packets were used, although this period included the winter season, during the early part of which the weather was worse than had been known for more than sixty years. The vessels which were built expressly for this purpose were strengthened by diagonal framing upon the plan of Sir Robert Seppings.
The next important stage may be considered to be the build ing of the " Great Western" at Bristol in 1838, a larger steamer than had then been built, being nearly 1400 tons ; and the first voyage by steam across the Atlantic. The tonnage of the Great Western equalled that of the largest sailing merchant ships which had been constructed. She left Bristol, and entered New York harbour under full steam in the extraordinary period of 5 days having on board a surplus of 148 tons of coal. It is true that the Sirius, a smaller steamer, had sailed from Cork before the Great Western left England, and had arrived in safety at New York just before her ; but there was this important difference between the two voyages, the Sirius had performed much of lier's under sail, while the Great Western had been propelled by steam only. Fourteen years
later a large ship called the Australian, built of iron, on the Clyde, left Plymouth (June, 1852) for Melbounie touching for coals at St. Vincent, St. Helena, and the Cape, and anchored safely in King George's Sound, West Australia, on the 20th of August, having per formed the whole voyage (including stoppages for fuel) iu 76 days. This was the first attempt to reach Australia by steam, and led to the construction of such ships as the celebrated Great Britain, the ill-fated Royal Charter, and other ships of greater perfection. In 1854 a fine American paddle-wheel ship called the Golden Age, astonished our Liverpool builders by her size and power, and gave the first intima tion of a change in form likely to become general among ocean steamers. The total omission of a bowsprit and the relief afforded the fore part of the ship as a floating bulk, by the removal of the usual dead wood about the stem and figure-head, was a change deduced from scientific experiments becoming more and more followed. The Golden Age had taken in at one port alone (Tahiti) about 1200 tons of coal, an enormous weight, double that which only 15 years before had been the supply to the Great Western.
Another memorable event in the history of ocean steamers was the voyage of the steam screw ship Argo of 1850 tons, which at about this period circumnavigated the globe, the duration of her actual voyage being only 124 days.
Since this period a number of gigantic ocean steamers have been built for the companies known as the Peninsular and Oriental, the Royal West India Mail, the Cunard, &e. Among these the Persia is the largest of paddle steamers. Some of these magnificent vessels are of about 3500 tons, fitted with exquisite taste and elegance. But the greatest triumph of naval architecture, and the most extraordinary as to size is the Great Eastern, built in 1859 by Mr. John Scott Russell, on the Thames, from the joint designs of himself and Mr. Brunel. This stupendous vessel Is of the length of 691 feet on deck, has a breadth of 83 feet and depth of 58 feet, having a gross registered tonnage of 18,914, but said to be capable of carrying 25,000 tons I The most prominent events in the history of steam vessels having been thus mentioned, a few general remarks will show the actual position of this important subject.
It is, perhaps, impossible to over-estimate the importance of the building of the Great Eastern as an iron ship. In many prior eases steam ships had been saved from foundering by being built of metal. The writer was one who encountered the fearful hurricane of September, 1553, in the Ravensbourne in the North Sea, and long previous experience of the sea enables him to declare that no vessel built of wood could have braved such a prolonged tempest with impunity, inasmuch as the twistings of the frame of the ship must have started treuails and butt ends, to her inevitable destruction, and that of the crow and passengers. The well-known instance of the Great Britain lying a whole winter on shore In Dundrum Bay, exposed to the action of heavy surf, is a powerful fact in favour of iron ships. The introduction of water-tight compartments has also long been a consideration. Steam vessels are greatly strengthened by means of these water-tight bulkheads or transverse partitions in the hull, the general adoption of which, more than any other improvement, increases the safety of steam navigation. In a vessel of the ordinary construction a small local injury from striking upon a rock, from collision, or from any other cause, may occasion the sinking of the the water has free access to every part of it. Fire also, wherever it may commence, is pretty sure to spread through the whole length of the boat. The adoption of water-tight bulkheads, to confine the effect of an accident to the particular division of the vessel in which it origin ates, was suggested by Dodd as early as 1818. Ile mentions them in p. 220 of the treatise which has been alluded to in the former part of this article, proposing to use them between the engine-room and the cabins; and he states that he intended to introduce them in two boats which he was then building. Whether he did so or not we are unaware; but the adoption of this excellent precautionary apparatus appears to be due to Mr. C. W. Williams, managing director of the City of Dublin Steam-packet Company. A minute description of his bulkheads, and a very satisfactory statement respecting their import ance and their efficiency, are given in a communication from that gentleman to the commissioners on steam-vessel accidents in 1839, which is printed in the appendix to their report. He therein states that he first applied watertight bulkheads in an iron steamer called the Garryowen.