The _Roosevelt_ had engines capable of developing one thousand horse-power. They were of the inverted, compound type, driving a single eleven-foot propeller, and steam was supplied by two water-tube boilers and one Scotch boiler. Her sail plan is a light, American, three-masted schooner rig, possessing the advantage of light weight (it is to be remembered that every pound of weight saved in rigging or fitting means a pound of coal in the hold), and small surface to be forced through a head wind; yet sufficient to materially help the engines in a favouring wind, and to enable the ship to make her way home should her coal be exhausted. As to construction: The strength of the hull must be such that it will resist the terrific pressure of the ice-floes, and keep its shape intact until the lifting of the ship bodily releases the pressure; such that if supported at each end only, or in the middle only, or thrown up on the ice and resting upon her bilge, during the paroxysms of the floes, she will not be strained or injured; and such that she can ram the ice by the hour when necessary, without injury to seams or fastenings. It is a popular fallacy that steel is a suitable material for the construction of an Arctic ship. A steel ship, though structurally strong, is peculiarly vulnerable locally to the ragged, rock-like tongues and corners of heavy Arctic ice. The elasticity, toughness and resiliency of thick wooden sides are essential in an Arctic ship; but the wood planking may be steel-sheathed on the outside to enable the ship more easily to slip from the grip of the ice, and the methods of composite ship building may be utilised in the interior of the vessel, to reduce weight, while at the same time increasing its structural strength, and not lessening the strength and rigidity of the interior bracing. In the interests of strength, the frames of the _Roosevelt_ were made treble, keel, keelson, stem and stern-post exceptionally strong; the planking is double; the deck beams, and especially the ’tween-deck beams, which are to be just below the water-line, are extra heavy, and spaced more closely than usual. Additional struts from the bilges, and strong posts from the keelson, longitudinal tie plates at the waterways and on the upper-deck beams, and transverse bulkheads, add still further to her great strength. In the interest of lightness there is no ’tween-deck planking, no interior fittings; and the spars and rigging are made as light as possible. The keel, false keel and keelsons are of oak, and form a rigid backbone to the ship six feet in height. The stem and rudder and propeller posts also are of massive oak timbers, the former having a depth on the ship’s axis of seven to ten feet, to take the blows when ramming ice. The frames also are of oak, placed almost close together, and each composed of three thicknesses of timber bolted together to give great strength. The planking is double, yellow pine inside and oak outside.