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following very noticeable results. When a boat heels over 30 
degrees, the pressure is diminished by about %, when she heels 
over 45 degrees, by about 24, when she heels over 60 degrees, 
by about 7%, of its original amount. Hence a boat should have a 
_ fairly high side, and be well decked in, so that she may heel over 
to a high angle without swamping. Besides, her stability should 
go on increasing up to 50 degrees or 60 degrees, so that the 
resistance may be strengthened as the attack is weakened. A good 
power of recovery when heeled over to a high angle is the essential 
element of safety. A well designed boat has this power, and an 
ill designed boat, or a row boat with sails up has not. The one is 
almost absolutely safe with reasonable care ; the greatest skill and 
watchfulness cannot quite ensure this safety to the others. 
The stability suited to a sailing boat, that which goes on 
increasing up to a high angle of heel, can only be given by a heavy 
weight carried low. Racing yachts are so ballasted that the 
centre of gravity is but very little above the centre of buoyancy ; 
in some yachts, and as I should judge, in most of the Windermere 
racers, it is actually below it. Referring to our first rough con- 
ception of stability in connection with Fig. 3, we shall see that if 
G be originally as low as C, the vertical line through G will not 
move towards C as the vessel heels over; and if G be lower than 
C, the vertical line through G will recede from C rather than 
approach it. Hence the chief cause which puts a stop to the 
increase of stability at high angles will be removed if G be by 
efficient ballasting got well down. In this way a stability increasing 
up to 50 degrees or 60 degrees may be obtained without prejudice 
to speed, and this is more than enough for all practical require- 
ments. It is seldom advantageous to sail a boat at a greater 
angle than 30 degrees, and between 30 degrees and 60 degrees _ 
there is a wide margin to cover all accidental risks. 
In a flat floored boat the ballast can never be got down very 
far below the water line, so that the centre of gravity cannot be 
low, especially if, as is the case in regular sailing boats, a consider- — 
able weight in mast, spars, sails, and rigging be carried at some — 
height above the water. Hence the flat floor, the best form for , 
