Mr. Hugh L. Cooper will speak in the Living Room of the Union this evening at 8 o'clock on "Water Power and Man Power." His talk will be illustrated by stereopticon slides. Mr. Cooper is one of the foremost engineers of the country. Among other feats, he drove a tunnel under the Horseshoe Falls at Niagara, which was considered an impossible task. Perhaps his most important exploit was the planning and building of the great water power dam across the Mississippi at Keokuk, Iowa. The dam is nine-tenths of a mile long, being made up of one hundred and nineteen arched spans.

Mr. Cooper will lecture at the Assembly Luncheon of the Boston Chamber of Commerce this noon, and at Technology this afternoon. Members of the Union will be welcome this evening.