“Self-righting” is, of course, a most important principle in life-boats, and out of some 250 boats of the Institution there are scarcely more than twenty which do not possess it. Up to twenty years or so ago it was derided by many otherwise practical men. Yet as early as 1792 we find the Rev. James Bremner, of Walls, Orkney, proposing to make all ordinary boats capable of righting themselves in the water by placing two water-tight casks, parallel to each other, in the head and stern sheets, and by affixing a heavy iron keel. The self-righting power of to-day is obtained by the following means. The boat is built with considerably higher gunwales at the bows and stern than in the centre, while four to six feet of the space at either end are water-tight air-chambers. A heavy iron keel is attached, and a nearly equal weight of light air-cases, and cork ballast cases are stowed betwixt the boat’s floor and the deck. “No other measures are necessary to be taken in order to effect the self-righting power. When the boat is forcibly placed in the water with her keel upwards, she is floated unsteadily on the two air chambers at bow and stern, while the heavy iron keel and other ballast then being carried above the centre of gravity, an unstable equilibrium is at once effected, in which dilemma the boat cannot remain, the raised weight falls on one side or the other of the centre of gravity, and drags the boat round to her ordinary position, when the water shipped during the evolution quickly escapes through the relieving tubes, and she is again ready for any service that may be required of her.” Nearly all life-boat stations are provided with a transporting carriage, built especially for the particular boat. The use of this, in many cases, is to convey the boat by land to the point nearest the wreck. On some coasts the distance may be several miles. In addition to this, a boat-carriage is of immense service in launching a boat from a beach without her keel touching the ground; so much so, indeed, that one can be readily launched from a carriage through a high surf, when without one she could not be got off the beach. The carriage is often backed sufficiently far into the water to enable the boat to float when she is run off. [Illustration: A life-boat and carriage—latest form.]