Larger fin-keel boats have been projected, and one of 45 ft. length on water-line has just been built, but their success from a general view-point is highly questionable. Mr. N. G. Herreshoff, in 1883, introduced a very useful rig, which was first tested to his complete satisfaction on 'Consuelo.' These boats are styled 'cat-yawl,' and since their introduction the type has become very popular, and most deservedly so, as for ordinary sailing, and particularly cruising, the rig offers many important advantages. In reefing the mainsail is accessible, and the absence of the long boom of the cat-boat is readily appreciated. The rig of the cat-yawl has been applied successfully to all designs of yacht, deep and moderate beam as well as the shallow broad type, and always with increasing satisfaction. The rig, however, seems to be confined to boats not over 40 ft. length on water-line, as, the mainmast being placed so near the bow, it is impossible to stay it, and too large a mast unstayed is not desirable in a cruising boat. [Illustration: Herreshoff catamaran.] The proportions between the mainsail and jigger as recommended by the projector is 4 in the former to 1 in the latter--that is, the dimensions of the jigger should be exactly one-half those of the mainsail. Mr. Herreshoff is also responsible for another marine curiosity that appeared in 1876. This was a catamaran or double-hulled boat--intended to be handled by one man. This boat differs from its kinsfolk of the southern ocean, the point of widest departure being that the hulls are connected by flexible means, so that each hull can adjust itself to the surface of the water it moves in. The means employed in forming this flexible union were through the agency of a complex system of ball-and-socket joints which had range of motion enough, so that one hull might be riding a wave, whilst its sister would be in the depths of a hollow. A small tray-shaped car for passengers, and the mast and rigging, were supported between and above the hulls by a system of truss-work with adjustible tension rods of iron. These catamarans carried a mainsail and jib, and in smooth water made wonderful speed; 21 miles an hour has been attained under favourable conditions. This aquatic marvel was not destined to become popular; the boats required special skill in their management, and were best calculated for an afternoon's sail in smooth, sheltered water. The absence of anything like cabin accommodations was also against their use, but cruising has been successfully accomplished in them through the use of a tent to make shelter, covering the car, and of sufficient height for one to stand under it. [Illustration: Newport (centreboard) cat-boat.]