104 THE SEA. 



Archimedes made the trip in less time than it had ever previously been performed by any 

 of the mail packets. Captain Chappell, R N., afterwards took her clear round England 

 and Scotland, calling 1 at numerous ports. The Admiralty at length ordered the construction 

 of a screw vessel, ani the lines of the Rattler were laid down on the same model as the 

 Alecto, a paddle-wheel steamer then building. 



Another claimant as an inventor, who should be mentioned most honourably, is Mr. 

 Woodcroft, some of whose experiments were being patented in 1826. They were not 

 tried on a suitable scale till after the successes of Ericsson and Smith. Woodcroft's 

 " varying pitch screw-propeller/' patented in 1844, the title of which describes itself, is 

 to-day "considered the best and most useful type." 



In following the progress of the screw, as applicable to the propulsion of merchant 

 vessels,* and its use in other countries, we 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, 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 impressed 

 with the value and utility of the discovery, that, although he had only made 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 ow r n 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 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 his 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 an 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 the boats, named after her owner, the 

 Robert F. Stockton, was built 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 propellers 6 feet 4 inches 



* The above account is derived from Lindsay. 



