SOCIAL LIFE AT PALM BEACH.' • • ♦Special to The New York Times.PALM BEACH, Fla., Feb. 21.—This week many prominent New Yorkers have arrived Imre. H. MeK. Twombly and James Henry Smith are at the Hotel Royal Poineiana, each with a party. Col. John Jacob Aster arrived in his private car and has attended several small functions. James R. Keene is renewing the acquaintance with• # S I » 0 * 'Palm Beach which he made last seasonand found so pleasant.A party of young New Yorkers who h^ve j ist returned from a trip to Cuba and are at Palm Beach, includes Bradish Johnson, William Fitz Hugh Whitehouse, and De-lancey Kountze. The latter is the guest of Mr. and Mrs. Eugene M. O’Neill of Pittsburg at their beach cottage. The O’Neills are also entertaining Miss Martha Jdhn-son of Macon, Ga., a cousin of Mrs. Cornelius Vanderbilt.• • * • •August Belmont and Edward Clarkson Potter of New York arrived at the Breakers together early this week. They expect to remain about a month, seeking rest In fishing and other pleasures of the quieter kind. Mr, and Mrs. O. H. P. Belmont, and the letter's son, Harold Vanderbilt, have been at the Hotel Royal Poincl-ana for about two weeks.. Young Mr. Vanderbilt and Mr. Worthington Whitehouse are constant companions. They swim together in the surl’ every morning, play tennis, and are among the most industrious of the dancers at the al fresco affairs that are held three times a week. The Duke and Duchess of Manchester are also amongthe dancers. CThe Duke was chief judge at a cake walk