Like his father he showed studious interest in chemistry, physics, and mechanical engineering. Shipbuilding attracted his attention for a time and, when he was about seventeen, he was sent to the United States to increase his knowledge of mechanics, as applied to ships, by association with John Ericsson. At the home of the latter on Franklin Street, New York, where a tablet has been placed to commemorate the services of this inventor in the Civil War, young Nobel lived for a time. His father sent him to John Ericsson in order to investigate an invention of his, an engine which was supposed to work by heat from the sun. He stayed several months, probably not more than a year. Ericsson was passing through a period of fluctuating fortunes. At the end of 1849 his balance was only $132.32--his total receipts for the year had been but $2,000. Two years later he recorded a balance of $8,690.10. In the interval he had sold several patents and had received congratulations from the King of Sweden upon the great future for his “test caloric engine.” This was the goal of his experiments during these years; its success was to be tested in the trial trip of _The Ericsson_, February 11, 1853. A squall came up as the boat was launched and making headway, and it sank, carrying with it hopes of the inventor after years of experiment, and half a million dollars of invested capital. Ericsson was crushed for a few weeks. How pluckily he recovered his courage, made his plans for _The Monitor_, offered that to the United States government and won success for the cause of the North, is familiar history.[2]