HELMERSEN, GREGOR VON Russian geologist, was born at Laugut-Duckershof, near Dorpat, on Sept. 29 (O.S.) 1803. He received an engineering training and became major-general in the corps of mining engineers. In 1837 he was appointed professor of geology in the mining institute at St. Petersburg. He wrote Studien fiber die Wanderblocke and die Diluvialgebilde Russlands (1869 and 1882). Most of his memoirs were published by the Imperial Academy of Sciences at St. Petersburg. He died at St. Petersburg on Feb. 3 (O.S.) 1885.