Two COMMONWEALTH BUILDERS. out its extent and depth by means of terraces along the Col- umbia River and the ocean. "Professor Condon's book, 'The Two Islands,' 5 is a popu- lar account of the geological history of the original 'Oregon Country.' The Klamath mountain group of Southwestern Oregon and Northern California was an island (Siskyou Island) in the Cretaceous sea, separated from the Sierra Nevada by Diller's Lassen Strait. The Blue Mountains, how- ever, were not an island (Shoshone Island) at the time, for only in the Upper Cretaceous (early Chico) did the sea reach even the western part of the Blue Mountain region. But Con- don's treatment of the subject brought out the striking geo- logical difference between the two mountain groups and the rest of the State, showing that they are two regions of Paleo- zoic and Mesozoic rocks surrounded by Tertiary lavas and sediments. "Thomas Condon was born in Ireland, March 3, 1822. When he was eleven years old, the family moved to New York City ; later to the central part of New York State, where Con- don finished his education, taught school, and made a collec- tion of New York paleozoic fossils which later formed the nucleus of his splendid collection at the University of Oregon. He graduated from Auburn Theological Seminary in 1852, married Miss Cornelia Holt, and sailed for Oregon by way of Cape Horn. "For several years he had charge of the Congregational Mission at The Dalles, Oregon, then a small trading post. It was while stationed at The Dalles that Condon made most of his trips into the interior, generally with military parties, gathering the fine Tertiary mammals in his collection. In 1872 he became professor of geology and natural history at Pacific University, resigning in 1876, to accept the same chair in the newly created University of Oregon. Here he remained until 1905, confining his teaching in later years mainly to paleontology. In these last years Professor Condon was too feeble to go into the field, but he had become so well known that people in all parts of the State were constantly sending him new specimens, knowing well the pleasure these gifts brought to the old naturalist who no longer could gather them himself. They were fresh links to the outdoor world, to the scenes of his early activities that he so enjoyed in memory. 5 "The Two Islands and What Came of Them." (Portland, Ore.: The J. K. Gill Co., 1902.)