THREE:Still, on the whole, the siege progressed favorably. Large supplies of food and ammunition were indispensable to Frederick. Thirty thousand hungry men were to be fed. A constant bombardment rapidly exhausts even abundant stores of powder, shot, and shell. Commencement of the Sixth Campaign.The Fortified Camp at Bunzelwitz.Skillful Engineering.Unintermitted Toil of the Soldiers.Retreat of the Russians.Loss of Schweidnitz.Peculiar Treatment of General Zastrow.Close of the Sixth Campaign.The King at Breslau.Desponding Letter to DArgens.Death of Elizabeth of Russia.Accession of Peter III.His Marriage with the Daughter of a Prussian General.Takes the Baptismal Name of Catharine.Assassination of Peter III.Curious Proclamation by the Empress.Commencement of the Seventh Campaign.Alliance of Russia with Prussia.Withdrawal from the Alliance.Termination of the War.