THE centenary of a society being by common consent an occasion for pride, encouragement, and hopeful anticipation, it follows that at a sesqui-centenary these accompaniments should enjoy a proportionate increase. With this advantage in prospect, the Manchester Literary and Philosophical Society, founded in February 1781, will celebrate its one hundred and fiftieth anniversary on Tuesday, Mar. 17, when Sir J. J. Thomson—himself a native of Manchester and an alumnus of Owens College—will deliver an address at 4 P.M. in the Athenum Hall. An honorary member since 1895, he will be presented with the Society's Dalton Medal, the last award of which was made in 1919 to Lord Rutherford, who, but for the call to Cambridge, would have been president for that and the following year. There will be a dinner the same evening in the Midland Hotel at 8 P.M. During the week, after Tuesday, the Society's house, No. 36 George Street, will be open to visitors from about 11 A.M to 5 P.M.