184 REPORT—1862. 
to be imperfect, there has arisen internationally a necessity for its adoption until 
it shall be met or superseded by some other device; and the object of the author, 
by this paper, is to bring before the notice of the British Association for the 
Advancement of Science the question, which has been otherwise publicly agitated 
by him, whether the ae of “invulnerability,” as based on “ armour-plating,” 
may not be superseded by the ere of “unsinkability,” as based on the 
principle of constructing ships with such a mass of uninflammable materials of a 
specific gravity less than that of water as shall support the hull and its entire load, 
and float, however perforated by shot laterally through the sides of the ship, or 
vertically through the deck and bottom of the vessel by the still more formidable 
effect of an improved mortar-practice pitching shells of great weight with an in- 
fallible precision at short range, or even still float in parts when severed by the 
concussion of a hostile ram. 
Though the vessel may thus be “ unsinkable,”’ it is not professed or anticipated by 
the author that war would be prosecuted without the sacrifice of blood; for though 
the proposed construction of shipping would be well adapted for protecting the 
crews of ships from small arms, still the cannon or the mortar would take effect. 
The chief point on which the principle of “unsinkable ships” is put forward by 
the author as claiming consideration is that, by the adoption of this principle, the 
whole crew of a ship would not be simultaneously drowned through the effective 
gamers of a single shot, shell, or ram-stroke, as might be the case with armoured 
ships, seeing that the direct fire of artillery is still paramount, and the mortar prac- 
tice above referred to has not yet been tried. 
A further advantage consequent on adopting the principle of “ unsinkability ”’ 
would be that it does not necessitate the construction of ships of such large size as 
is required for carrying out the principle of ‘invulnerability ” by armour-plating. 
Also by avoiding top-weight, by which armour-plated ships are so much encum- 
bered, many difficulties in the prosecution of naval architecture are obviated. It is 
therefore conceived that this principle of “unsinkability” would be well adapted 
for gun-boats and mortar-vessels destined to act in cooperation with each other in 
assailing larger vessels at close quarters, or doing service in shoal waters, such 
vessels receiving their stores from high-speed steamers of ordinary build acting as 
store and hospital and barrack ships, to be kept out of harm’s way. Also the prin- 
ciple of unsinkability would be well adapted for troop ships and the safe convey- 
ance of valuable cargoes and treasure. 
The details of construction of the “ unsinkable ship,” as respects the disposal of 
its unsinkable materials, will be dependent on the purpose for which the ship may 
be especially intended. For example, the whole mass of material on which the ship 
depends for its unsinkability may be in a solid mass, with the whole of its hold 
accommodation above the deep-draught water-level; or the vessel may haye a hold 
below the level of the load water-line, provided that the required mass of buoyant 
material be otherwise disposed of, constituting the sides or ends and bottom and 
decks of the vessel. Of course such a vessel with a hold below the load-line level 
may become water-logged, and, if a steamer, disabled ; but still such a vessel would 
sail, and the crew would be alive to do good service from her deck; at all events, 
her whole crew could not be simultaneously sent to the bottom, which is the great 
catastrophe intended to be obviated by the principle of unsinkable ships—a cata- 
strophe to which armour-plated ships, though bulkheaded, will be liable if artil- 
lery or mortar practice become paramount. 
The required brevity of this abstract does not admit of the details of calculation 
and of construction for the production of “unsinkable ships” of given capabilities 
being here entered upon; such an exposition, to be complete, would be elaborate, 
and may engage the future attention of the author. 
On Coryton’s Vertical- Wave-Line Ships, Self-Reefing Sails, and Guide-Pro~ 
peller. By Joun Coryton, of Lincoln’s Inn, Barrister-at-Law. 
The object of the inventor has been to produce a form of vessel which shall com- 
bine the weatherly qualities of a clipper ship, with the advantages of increased speed 
when going free, and greater safety when scudding before a gale, riding at an 
