HISTORY OF MARINE ARCHITECTURE.

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an outrigger constructed according to the Indiaa system, sufficient to balla-nce, orbecome equivalent to the support taken away ; such a vessel woaid nndoiafetedly.possess velocity and stability, in a far superior degree to what it did when in itsperfect state. The reason is almost too obvious to render any explanation necessary:nearly one moiety of the head resistance, or to speak more intelligibly, the oppo-sition made by die water to the passage of an heterogeneous body -through k,is consequently lessened, and therefore the velocity, provided the same quantumof impulse is used, becomes increased in a ratio equal to the diminution of theopposition. In addition to this, the fluid acting horizontally, and on that accountpreventing thepassage of a flat, or even surface through it, much more forciblythan it would, if compelled to act obliquely by the convexity of the surface pre-sented to it, it follows that such a vessel, if it were capable to extend the theoryfar beyond that scale which seems to have found nearly its utmost limits in theIndian Ocean, would suffer far less deflection from its intended course, than onebuilt according to the European method. This case and theoretical propositionseems to combine all the principles on which stability is founded, and all furtherargument consequently becomes useless.

It is incumbent, however, to offer some explanation, and indeed apology, in thisplace, for the use and introduction of the term stability in a new sense. As alreadyremarked, it has been hitherto applied in common, or at least very frequentlyconfounded, and indiscriminately used with stiffness; but however closely theyare, as there is a manifest difference in the qualities, so should there be adistinction in the terms also. Let not therefore the substitution of the wordstability, in expression of the same meaning with weatherly, the term generallyused by seamen, be considered as an unwarrantable affectation ; for the nauticalword is by no means so expressive and intelligible to the mathematician, ormarine architect, who, in all probability, may never have been at sea, as thatwhich is adopted in its room. The different senses and applications of the twoterms, which in the course of a few preceding pages have been in such frequentuse, have been already pointed out so fully, as to render it needless to say more,than that a vessel, drawing very little water, and having consequently a greatbreadth of floor, may be exceedingly stiff; so that the hull in itself would verytrivially yield to the lateral impulse of the wind, but drive very considerably toleeward; while on the other hand, a ship may be, in some measure, what is con-sidered crank, and yet deflect in no great degree from her appointed course.Vql. III. 3 G Expe-