By the time he had finished speaking I had snatched the glass from its beckets, and was half-way up the weather main rigging, while the watch was sheeting home and hoisting away the topgallant-sails and royals. When Keene reappeared on deck, after calling the skipper, I was comfortably astride the royal-yard, with my left arm round the spindle of the vane--the yard hoisting close up under the truck.  With my right hand I manipulated the slide of the telescope and adjusted the focus of the instrument to suit my sight.