Although the successful performances of the Archimedes brought the screw into more general notice, it does not appear that she was ever employed as a trading vessel. After several experiments she lay for a long time in the East India Dock advertised for sale, and her spirited proprietors, who had been so instrumental in promoting the introduction of the screw-propeller, lost all the capital they had invested in this important undertaking.
The Rattler and the Alecto, 1843.
As the Widgeon and Archimedes differed materially in size and form, an exact comparison could not be made by them between the performance of the screw and that of the paddle; but the result of these trials nevertheless showed (especially when the peculiar fitness of the screw for war purposes was taken into consideration) the propriety of having a further and fairer trial of this novel instrument. With this object in view the Rattler was ordered to be built,[142] and, that the experiment might be conclusive so far as a trial could be made between two vessels, she was constructed on the same lines as the Alecto (her after part being lengthened for the insertion of the screw), and fitted with engines of the same power, and on a plan which had been previously tried with paddle-wheel vessels.
The river trials of the Rattler lasted from October 1843 to the beginning of 1845, and showed that the screw-shaft might be advantageously reduced in diameter, and the blades by about one-third of their length, an alteration which greatly reduced the weight of the screw, and facilitated the operation of shipping and unshipping it, while rendering unnecessary the wounding to so great an extent of the after part of the vessel. Before, however, this last point was decided (it not being evident that the good performance of the shorter screw was not attributable to the greater clearance which the reduction of its length had caused), the screw aperture was partly filled up in a temporary manner, so as to leave the shorter screw the same clearance as the longer one had originally. The result of this experiment proved that the aperture in future vessels might be constructed of very moderate dimensions without lessening the propelling power of the screw.
The Rattler not as successful as expected.
These trials clearly showed that the screw, as an instrument of propulsion in smooth water, is not inferior to the paddle-wheel. But further experiments were considered necessary to establish its superiority in all respects. In the early part of the year 1845 the Rattler proceeded, in company with the Victoria and Albert and the Black Eagle, from Portsmouth to Pembroke. When rounding the Land’s End, and steaming against a strong head wind, both these vessels, as might be expected, showed a great superiority, their power being much greater than the Rattler’s in proportion to the resistance, and their paddle-floats being constructed on the feathering principle. This comparative failure of the Rattler left an unfavourable impression as to the efficiency of the screw against wind and sea in heavy weather, and this impression continued for several years, although when next tried in a run from the Thames to Leith, she showed in respect to speed a decided superiority over one of the paddle-wheel vessels employed in that trade, whose power as compared with her tonnage was greater than that of her competitor. Before joining the squadron under the command of Rear-Admiral Hyde Parker in July 1845, the Rattler was employed to tow the Erebus and Terror to the Orkney Islands on their fatal expedition to the North Pole, and she seems to have performed that duty to the entire satisfaction of Sir John Franklin.
Captain Robert F. Stockton efficiently supports Ericsson’s views.
In following the progress of the screw as applicable to the propulsion of merchant vessels, and its use in other countries, I must now recur to the period when Ericsson was making his experiments on the Thames. At that time an intelligent gentleman, Captain Robert F. Stockton, of the United States Navy, was on a visit to London. Being of an inquisitive turn of mind, like most of his countrymen, and fond of scientific pursuits, he watched with great interest the trials with the screw then in progress, and having obtained an introduction to Ericsson, he accompanied him on one of his experimental expeditions on the Thames. Unlike the Lords of the British Admiralty, who allowed eight years to elapse before they built their first screw-propeller, the Rattler, Captain Stockton was so strongly impressed with the value and utility of the discovery, that, though he had made only a single trip in the Francis B. Ogden, and that merely from London Bridge to Greenwich, he there and then gave Ericsson a commission to build for him two boats for the United States, with steam machinery and propeller as proposed by him. Stockton, impressed with its practical utility for war purposes, was undismayed by the recorded opinions of scientific men, and formed his own judgment from what he himself witnessed. He, therefore, not only ordered the two iron boats on his own account, but at once brought the subject before the Government of the United States, and caused various plans and models to be made at his own expense, explaining the peculiar fitness of the new invention for ships of war. So sanguine was he, indeed, of the great importance of this new mode of propulsion, and so determined that his views should be carried out, that he encouraged Ericsson to believe that the Government of the United States would test the propeller on a large scale; Ericsson, relying upon these promises, abandoned his professional engagements in England, and took his departure for the United States. But it was not until a change in the Federal administration, two years afterwards, that Captain Stockton was able to obtain a favourable hearing. Orders were then given to make the experiment in the Princeton, which was successful. The propeller, as applied to this war-vessel, was similar in construction to that of the Francis B. Ogden, as well in theory as in minute practical details.
One of these boats, named, after her owner, the Robert F. Stockton, was built of iron by Messrs. Laird of Birkenhead, and launched in 1838. She was 70 feet in length, 10 feet wide, and drew 6 feet 9 inches of water. Her cylinders were 16 inches diameter with 18 inches stroke, and her propeller 6 feet 4 inches in length. On her trial trips on the Thames, made in January of the following year, she accomplished a distance of 9 miles (over the land) in 35 minutes with the tide, thereby proving the speed through the water to be between 11 and 12 miles an hour. On her second trial, between Southwark and Waterloo bridges, she took in tow four laden barges, with upright sides and square ends, having a beam of 15 feet each, and drawing 4 feet 6 inches of water. One of these was lashed on each side, the other two being towed astern, and, though the weight of the whole must have been close upon 400 tons, and a considerable resistance was offered, also, by their form, the steamer towed them at the rate of 5½ miles an hour in slack water, or in 11 minutes between the two bridges, a distance of 1 mile.
These experiments having been considered in every way satisfactory, the Robert F. Stockton, of which the following is an illustration, left England for the United States in the beginning of April 1839, under the command of Captain Cram, of the American merchant service. Her crew consisted of four men and a boy, and, having accomplished the voyage under sail in forty days, Captain Cram was presented with the freedom of the city of New York for his daring in crossing the Atlantic in so small a craft, constructed only for river navigation.