The greatest boon, therefore, of modern times, ever given to the Arctic navigator, it may be safely, I think, said, was my Father’s invention of the _round top-gallant crow’s nest_. It was in May, 1807, I believe, in which the first of these was built. It was placed, in the first instance, at the top-mast head, but ultimately, when the invention became perfected, it was perched, like a rostrum, on the head of the main top-gallant mast, with nothing whatever above. This structure, as most approved by the inventor, is about four and a half feet in height and two and a half in diameter. The form is cylindrical, open above and closed below. The frame-work of the cylindrical part is covered with leather or canvas. The entrance is by a trap-hatch at the bottom. Arrangements are made for the depositing (sheltered from the weather) of various pieces of useful apparatus, such as speaking-trumpet, telescope, signal-flag, perhaps a rifle for shooting narwals, compass, etc. For the more effectual shelter of the observer when standing up, a moveable screen, two or three feet wide and adding a foot to the elevation, is placed on the windward side, and shifted whenever the ship is tacked, or the course materially changed. The protection thus obtained from the chilling action of the wind is most perfect. Not a breath of air stirs within this elevated rostrum. The observer has free use of all his limbs, and, being safe from the possibility of falling, has nothing to disturb him in giving his entire attention to the navigation of the ship and the look-out for whales. Being perched, too, on the most elevated part of the mast, there is nothing to interfere with his view of the whole area of the circle of vision, having, in clear weather, a diameter of twenty to twenty-two geographical miles. So supported, and so effectually protected, with the means of sitting, and space for moving about when standing, there is no particular hardship, in tolerable weather, in remaining at the mast-head for some hours together. Often has this elevated position been occupied by my Father, (and often by myself, too,) during ten or twelve hours, and sometimes fourteen hours or more, within the twenty-four. This invention has not only added unspeakably to the comfort and security of the officer at the mast-head, but has, no doubt, contributed greatly both to the safety of ships navigating the Arctic ices, and, in respect of its position for “a good look-out,” in no inconsiderable degree to the prosperity of their adventures.