It is rumored again that a survey is soon to be made through the heaviest portion of the Black Canon of the Gunnison. For a long distance the walls of syenite rise to the stupendous height of 3,000 feet, and for 1,800 feet the walls of the cañon are arched not many feet from the bed of the river. If the survey is successful, and the Denver and Rio Grande is built through the cañon, it will undoubtedly be the grandest piece of engineering on the American continent. The river is very swift, and it is proposed to build a boat at the western end, and provision it for a length of time, allowing it to float with the stream, but controlled by ropes. If the boat goes, the chances are that the baby road goes, too.--_Gunnison (Colo.) Review_. * * * * * THE ANCIENT MISSISSIPPI AND ITS TRIBUTARIES. [Footnote: This lecture was delivered in the Chapel of the State University, at Columbia, as an inaugural address on January 10, 1883, and illustrated by projections. The author has purposely avoided the very lengthy details of scientific observation by which the conclusions have been arrived at relating to the former wonderful condition of the Mississippi, and the subsequent changes to its present form: as a consideration of them would not only cause him to go beyond the allotted time, but might, perhaps, prove tiresome.] By J. W. SPENCER, B.A.Sc., Ph.D., F.G.S., Professor of Geology in the State University of Missouri. Physical geology is the science which deals with the past changes of the earth's crust, and the causes which have produced the present geographical features, everywhere seen about us. The subject of the present address must therefore be considered as one of geology rather than of geography, and I propose to trace for you the early history of the great Mississippi River, of which we have only a diminished remnant of the mightiest river that ever flowed over any terrestrial continent. By way of introduction, I wish you each to look at the map of our great river, with its tributaries as we now see it, draining half of the central portion of the continent, but which formerly drained, in addition, at least two of our great lakes, and many of the great rivers at the present time emptying into the colder Arctic Sea.