ON the 26th of July, 1864, a magnificent yacht was steaming along the North Channel at full speed, with a strong breeze blowing from the N. E. The Un-ion Jack was f lying at the mizzen-mast, and a blue standard bearing the initials E. G., embroidered in gold, and surmounted by a ducal coronet, floated from the topgallant head of the main-mast. The name of the yacht was the DUNCAN, and the owner was Lord Glenarvan, one of the sixteen Scotch peers who sit in the Upper House, and the most dis-tinguished member of the Royal Thames Yacht Club, so famous throughout the United Kingdom.