There are also toggels of another kind, employed to fasten the top-gallant sheets to the span, which is knotted round the cap at the top-mast-head. For as the lifts of the topsail-yard are out of use when the topsail is hoisted, they are always converted into top-gallant sheets, to render the rigging at the mast-heads as light and simple as possible. Before the topsail-yards can be lowered so as to be sustained by their lifts, it therefore becomes necessary to transfer that part of the lift to the top-mast-head, that so the whole weight of the yard may be sustained by its mast-head, and no part thereof by the top-gallant-yard, which would otherwise be the case. This is performed by fixing the double part, or bight of the lift, within the eye of the span above mentioned, and inserting the toggel through the former, so as to confine it to the latter, which operation is amongst sailors called putting the sheets in the beckets.
TOMPION, (tampon, Fr.) a sort of bung or cork used to stop the mouth of a cannon. At sea this is carefully encircled with tallow or putty, to prevent the penetration of the water into the bore, whereby the powder contained in the chamber might be damaged or rendered incapable of service.
TONNAGE. See the article Burthen.
TOP, hune, a sort of platform, surrounding the lower mast-head, from which it projects on all sides like a scaffold.
The principal intention of the top is to extend the top-mast shrouds, so as to form a greater angle with the mast, and thereby give additional support to the latter. It is sustained by certain timbers fixed across the hounds or shoulders of the mast, and called the tressel-trees and cross-trees, the former of which are expressed by k, fig. 1. plate [VI]. and the latter by l, l, fig. 2. The plan of the top is represented in fig. 6. where g g represents the holes through which the top-mast shrouds communicate with those of the lower mast, as explained in the article Shroud.
Besides the use above mentioned, the top is otherwise extremely convenient to contain the materials necessary for extending the small sails, and for fixing or repairing the rigging and machinery, with more facility and expedition. In ships of war it is used as a kind of redoubt, and is accordingly fortified for attack or defence, being furnished with swivels, musketry, and other fire-arms; and guarded by a thick fence of corded hammocs. Finally, it is employed as a place for looking out, either in the day or night.
The frame of the top is either close-planked like a platform, or open like a grating. The former kind, which is exhibited in fig. 6. plate [VI]. is generally stronger and more convenient; but the latter is much better in tempestuous weather, as presenting a smaller surface to the wind when the ship leans over to one side, and by consequence being less exposed to its efforts.
In all ships of war, and in the largest merchantmen, the top is fenced on the aft-side by a rail of about three feet high, stretching across, and supported by stanchions, between which a netting is usually constructed, as appears by fig. 2. plate [VI]. The outside of this netting is generally covered with red bayze or red painted canvas, which is extended from the rail down to the edge of the top, and called the top-armour. By this name it seems to have been considered as a sort of blind, behind which the men may conceal themselves from the aims of the enemy’s fire-arms in time of action, whilst they are charging their own muskets, carabines, or swivels.
The dimensions of tops in the royal navy are as follow. The breadth of the top athwart-ships, q q, fig. 6. is one third of the length of its corresponding top-mast. The length of all tops, from the foremost to the after edge p p, is equal to three fourths of their breadth athwart; and the square hole in the middle is five inches to a foot of those dimensions. The tressel-trees and cross-trees extend nearly to the edge of the tops. See those articles.
Top-block. See Block and Mast.