Various nations claim the invention of the screw as applied to boats. At Trieste and at Vienna stand statues erected to Joseph Ressel, for whom the Austrians lay claim. Commodore Stevens, of New Jersey, is also said by Professor Thurston to have built and worked a screw-propeller on the Hudson in 1812. Whatever may be the final decision as to Ericsson's claim in this matter, there, can be no doubt as to the value of the services he rendered in building the Monitor. The suggestion of the Monitor was first made in a communication from Ericsson to Napoleon III., dated New York, September, 1854. This paper contained a description of an iron-clad vessel surmounted by a cupola substantially as in the Monitor as finally built. The emperor, through General Favre, acknowledged the communication. Favre wrote: "The emperor has himself examined with the greatest care the new system of naval attack which you have communicated to him. His Majesty charges me with the honor of informing you that he has found your ideas very ingenious and worthy of the celebrated name of their author." For eight years Ericsson continued working upon his idea of a revolving cupola or turret upon an iron-clad raft, but found no opportunity to test the practical value of the device. His time finally came when, in 1861, the Navy Department appointed a board to examine plans for iron-clads. The board consisted of Commodores Joseph Smith, Hiram Paulding, and Charles H. Davis. Ericsson, having learned to distrust his own powers as a business agent, engaged the assistance of C. S. Bushnell, a Connecticut man of some wealth, who went to Washington and presented the designs of the Monitor to the board.