or may not be fitted with motors. Large motor yachts sometimes carry racing tenders as well as substantially built and seaworthy ones. A representative type of a power and yacht tender is shown in Fig. 16.

57. A power canoe is a canoe in which a small motor is installed. In this type the canoe form is usually followed, although some later models are like the regulation speed boat, retaining only the light canoe construction.

58. Hydroplanes are lightly built racing boats of great power for their weight and so designed that they skim over the surface of the water when at speed, as shown in Fig. 17, instead of cutting through it. There are many forms of hydro

planes, some having steps or notches across the bottom, while others have a simple, smooth, flat, underbody. The latter class is known as the monoplane.

59. Of life boats, there are two classes, the first being carried by large vessels for the purpose of saving the crew and passengers in case of accident to the vessel; in the second class. are the boats used at the life-saving stations along the coast to rescue the crew and passengers from ships wrecked on the shore. Life boats of the first class are usually propelled by oars, while those of the second class are operated with motors in addition to an auxiliary rig of sail, as shown in Fig. 18. They are so designed as to right themselves automatically if overturned by a heavy surf.

60. Commercial Motor Craft.-Though largely used on pleasure craft, the gasoline motor is more extensively adopted

as the motive power for commercial boats. Especially is this the case among fishermen, not less than 75,000 motor boats being used at the present time by persons engaged in the fishing, oyster, and lobster industry. In fact, on small and mediumsized craft, in general, the sail and the steam engine is being replaced by the gasoline motor owing to its peculiar and advantageous adaptability for various commercial requirements. In Figs. 19 and 20 are shown a few of the many types of commer

cial motor craft in operation at the present time. In Fig. 20 (a) is shown a motor fishing boat; in (b), a salmon seine motor boat; in (c), a motor oyster boat; and in (d), a motor railway-car ferry. These craft are easily distinguished by the absence of funnels or smokestacks.

61. The proportion of power boats used for various commercial purposes to those used for pleasure appears greater on the Pacific Coast than in the East, possibly because the gasoline engine is admirably adapted to pioneering, no license being

required to operate it. On Puget Sound gasoline is displacing both sail and steam in business. In the halibut fishery it is employed for auxiliary power on sailing vessels. Gasoline

tugs are also coming in. Gasoline freight boats are common, and here and there one sees a gasoline packet boat carrying passengers. Greater numbers of gasoline boats are. used in

the fisheries on the Atlantic than in any other commercial pursuit, though the small gasoline freight boat is rapidly appearing.

NOTE. A more detailed discussion of the different types of motor boats classified according to their construction, deck arrangement, and use is given later.

ROPE AND LIGHT CORDAGE

KINDS OF ROPE

62. Manila rope is a cordage made from the fibers of wild banana, the entire supply of which comes from the Philippine Islands. This fiber is very strong and durable and is well adapted for the manufacture of small cordage. When dry, it contains 12 per cent. moisture and will absorb as much as 40 per cent. in damp atmosphere.

63. Hemp rope is made from the fibers of the hemp plant. The best hemp cordage is that manufactured from hemp grown in Russia. This rope is more flexible than manila but less strong and less durable. It decays rapidly if kept wet. Hemp rope is usually tarred, but when not tarred it is known as white rope. Tarring prolongs the durability of the rope but reduces its strength and flexibility. Manila ropes are never tarred.

64. Coir Rope. The fiber of the outer husk of the cocoanut, known as coir, is occasionally used in cordage manufacture; it is quite strong, but is short, stiff, coarse, and rough. On account of its buoyancy, and because moisture does not affect it, rope made of coir is particularly well adapted for tow ropes.

65. Cotton rope is extensively used in small crafts for halliards, sheets, and sundry purposes, being much softer than manila. It is spun three-stranded the same as manila rope, but often comes braided. Cotton rope when braided is strong and durable but stiff and awkward to handle, especially when wet.