34 o HISTORY OF MARINE ARCHITECTURE.

Seas; circumstances which are manifestly in favour of flat-floored vessels andsliding keels.

It is a point too well known to every person conversant in naval architectureto need explanation, how far the different constructions of vessels will occasion avariance in the quantity those actually of the same measurement will carry. Shipsbuilt sharp forward and aft, lose a considerable portion of stowage; while some ves*sels have the floor sp straight throughout the whole of their length, that bylooking down in the holds of one, and of the other, the difference is easily discernibleby the eye, For this reason it is impossible a true measurement ever can bemade; and the assertion may be regarded, perhaps, that notwithstanding allwhich the respectable and learned men of different nations have written on thesubject, no certain method will ever be discovered of ascertaining the true capacityof vessels, until they shall be built with greater resemblance to each other,even in the upper works, as well as in the lower part of the hull. It has,frequently been observed by officers and others, who have had occasion to informthemselves practically on the subject, that many ships of the same measurementwill not take in nearly the quantity they are estimated to carry ; while others,exclusive of the quantity of goods or stores, which their constructors allotted to-them, can receive a still additional cargo, and carry it with ease. It has beenobserved too, that if sharp-built vessels are at any time capable of containing theamount of their calculated tonnage, they are never able to carry it with the sameease that vessels of flatter construction are, inasmuch as their form forward andaft will inevitably occasion their pitching and shipping water. This inconve-nience has been observed to proceed invariably from the cause just assigned ; fora sharp-built ship sinks under its cargo so fast, that, by the time it comes to itsbearings, it is frequently not nearly loaded. Those having flat and long floors,on the other hand, sink slowly ; and, after having taken in the quantity theymeasure, will have, frequently, plenty of room, and remain high out of the W'ater rso that it has happened, not only that an additional cargo has been taken in,but that, when two vessels of the same measurement, though of contrary con-structions, have been laden at the same time, the flat-floored vessel has beenenabled to carry, in all respects fitter for sea, what was necessarily rejected by hercompanion ; and, after taking on board the whole of her additional cargo, stillcontinued in the best state of trim. It appears, therefore, to be theopinion of many ingenious naval architects, and of Captain Schanck in par-ticular, that one of the first desiderata in the improvement of the art of ship-building