her keel; and it is obvious that the lower the weight the more effective it will be. A deep boat with a heavy lead keel cannot capsize. She heels over readily to the wind at first, but becomes stiffer as the angle increases; for the more she heels over to the wind, with the greater leverage does her lead keel tend to right her again, and the greater force must the wind exert in order to heel her further. A Lake Windermere yacht, for example, can heel over till she lies flat on her beam ends, and yet rights herself briskly the moment the pressure of the squall diminishes.
On the other hand, a broad, shallow boat needs no ballast to enable her to float upright. Thus the ordinary, beamy, flat-floored, cat-boat of America, with its wooden centre-board, is as often as not sailed without ballast. Such a boat is very stiff at first; she does not heel readily; but having no heavy keel to right her, she capsizes so soon as she has heeled beyond a certain angle.
Of the effects of the wind on a vessel, the one which has to be utilised to the utmost extent is the propelling effect; therefore every boat is constructed so that the water may offer the least resistance to her forward motion. Thus the bow is made sharp, like a wedge, so that it cuts through the water easily and with little friction; while the stern is tapered off gently—the boat, if she be properly built, having what is termed a clean run, which enables the water to glide away from her
