At ten o'clock the guns in the Park fired a salute, and immediately after the Queen made her appearance at the window of the tapestried ante-room adjoining the audience chamber, and was received with deafening cheers--cheers all the more hearty that her appearance was a surprise, for few had known that she was to be there present. She was dressed in deep mourning, with a white tippet, white cuffs, and a border of white lace under a small black bonnet, which was placed far back on her head, exhibiting her light brown hair simply parted in front. She viewed the proceedings with intense interest, standing during the whole rehearsal of the Proclamation; and although she looked pale and fatigued, she returned the repeated rounds of cheers with great grace and dignity. All were touched to very tenderness of soul by the pale face, wet with tears, calm and simply grave, the gravity being enhanced by the plain black dress and bands of brown hair, giving an aspect of Quaker-like neatness. On either side stood Lords Melbourne and Lansdowne, in their state dresses and blue ribbons, and close to her was her mother, who was dressed similarly to the Queen. In the court-yard were Garter King-at-Arms, with Heralds and Pursuivants in their robes of office, and eight Officers-of-Arms on horseback, bearing massive silver maces; Sergeants-at-Arms, with their maces and collars; the Sergeant-Trumpeter, with his mace and collar; the trumpets, drum-major and drums, and Knights Marshal and men. On Her Majesty showing herself at the Presence Chamber window, Garter Principal King-at-Arms, having taken his station in the court-yard under the window, accompanied by the Duke of Norfolk as Earl Marshal of England, read the Proclamation, containing the formal and official announcement of the demise of King William IV., and of the consequent accession of Queen Alexandrina Victoria to the rule of these realms. The Proclamation was brief, and to the point:--