( 268 )

from the sides of a vessel being so sloped as tothrow off surges, and to cause the hearing to in-crease, steadily, up to the plane of floatation,)the advantage, with respect to stability, ofmaking the floating body wider towards the topthan at bottom, and of forming the upper works,and any deck or covering it may have, of lightmaterials.

Vessels of spherical shape, or cylindrical ves-sels floating with their axes horizontal, beingcompletely symmetrical, are indifferent with re-spect to position when unloaded, and have atendency to turn with the least weight placedupon them. They cannot, consequently, beused singly; and, however associated, the com-pound body is, as has been shown, very defectivein steadiness and stability.*

I insert, in the accompanying notes, theopinions and observations of foreign militaryengineers on these vessels.f The objection

* The reader, who is desirous of studying the principleson which depend the stability of floating bodies, will do wellto consult Dr. Gregory’s excellent treatise on Mechanics,chap. iii. vol. i.

f From Mr. Vaillant’s translation of the first edition of thiswork, page 77 .

“ Lorsque les troupes Anglaises etaient cn France avecl’armee d’occupation des puissances coalisees, dies ont faitI’cssai d’une nouvelle espcce de ponts, ayant pour chaque