AT a meeting of the Newcomen Society held at the Science Museum on April 19, in a paper entitled “The First Twenty Years of Screw Propulsion 1838-58”, Engineer Captain E. C. Smith gave some interesting information regarding the early inventors of screw propellers, Sir Francis Pettit Smith, John Ericsson, George Lowe, George Blaxland and Bonnet Woodcroft, whose names were most closely associated in the minds of their contemporaries with the early trials of sea-going screw-driven vessels and the adoption of the screw-propeller on a wide scale. It was appropriate, Capt. Smith said, that the subject should be dealt with at a meeting at the Science Museum, for Bennet Woodcroft was the virtual founder of that institution, while Smith was for some fourteen years the curator under Woodcroft. Both these pioneers were buried in Brompton Cemetery, and their tombstones mention their participation in the introduction of the screw. Ericsson's work began with his patent of July 1836, the building of the little Francis B. Ogden and then the slightly larger Robert F. Stockton. Soon after the trials of the latter in the Thames in 1839, she was sailed to America; Ericsson soon followed her and it was in the United States that his main work in connexion with screw propulsion was done, his most notable vessel being the U.S.S. Princeton, built in 1841-43. She was the first screw-driven warship ever launched. By 1850, about a hundred and fifty American vessels had been fitted with the screw. The most important work in England was done by Smith, but of this Capt. Smith is to deal with in a future paper. In an appendix to the paper prepared by Dr. H. W. Dickinson, Mr. A. A. Gomme and Mr. E. W. White, a review was given of the various law cases which arose out of the patents and over which a vast amount of time, energy and money were wasted.