an arrondissement of the department of the Upper Alps, in France, extending over 583 square miles. It is divided into five cantons and thirty-six communes, and contains 28,628 inhabitants. The capital, of the same name, is situated on the top of a steep rock, at the foot of which flows the river Durance. It has a cathedral, an episcopal palace, and a large prison; and contains 700 houses and 3133 inhabitants. Long. 6. 20. E. Lat. 44. 34. N.