Many other factors contributed to affect, in a manner always subtle and frequently inexplicable, the sailing qualities of a ship. The form of the body, the position of masts and the setting up of the rigging, the disposition of weights, the angle of the yards, the conditions of stability, all had their effect on the vessel’s motion, and therefore on her speed through the water. Free water in a ship’s bilge, for example, had an effect on her degree of stiffness, and from this cause her speed was not easily predictable. Charnock relates how, in the colonial wars of the late eighteenth century, an American vessel, the _Hancock_, was captured after an unprecedented chase, solely because her commander, injudiciously supposing that by lightening his ship he would enhance her swiftness, pumped water out of her. It was noticed, again, that in certain circumstances the speed of a ship increased when the crew turned into their hammocks. The lines of the ship were drawn without reference to any science of naval architecture, and merely by instinct and the accumulated experience of the builder; the laws of stability and of fluid resistance were at this time unknown. Experience indicated the desirability of a short keel, to make the ship turn quickly; of an ample rake forward from keel to beak-head--“more than a third the length of the keel, commonly,” says Sir Henry Manwayring, for, “a great rake forward gives a ship good way and makes her keep a good wind, but if she have not a full bow it will make her pitch mightily into a head sea.... The longer a ship’s rake is, the fuller must be the bow”; of a fine run aft, so as to let the water flow strongly and swiftly to the rudder and make the ship steer and sail well; of a narrow rudder, so as not to hold much dead water when the helm was over,--yet, “if a ship have a fat quarter, she will require a broad rudder.” The correct formation of the bow was recognised as of the greatest importance, and the most difficult compromise in the design of a ship. A bow too bluff offered much resistance to motion through the water; on the other hand, too sharp a bow lacked buoyancy, and, from the great weight of mastage, headsails, anchors, etc., which it had to support, caused a vessel to pitch badly in a head sea. “If the bow be too broad,” wrote Captain John Smith, in his _Sea Man’s Grammar_, “she will seldom carry a bone in her mouth, or cut a feather, that is, to make a foam before her: where a well-bowed ship so swiftly presseth the water as that it foameth, and in the dark night sparkleth like fire.”