BAR-SUR-SEINE, an arrondissement of the department of the Aube, in France, comprehending 5 cantons and 85 communes. Area, 357 square miles. Pop. in 1851, 53,447. The chief place of the same name has a population of 2656 persons, employed in manufactures and the wine trade. In the middle ages this was a place of considerable importance. Long. 4. 24. E. Lat. 48. 5. N.