water inside, and if so it is removed as far as practicable. If a small amount of water enters the deck or planking, means are taken to prevent the difficulty by a thorough repair.

At least one boat is loaded with weights corresponding to the full complement of persons and equipment. If water enters the boat after three hours, in such quantity as to become dangerous to the stability of the boat, efficient air-cases are fitted and provided in as large units as practicable, allowing three cubic feet of air-case for each person assigned to the boat.

The freeboard of the loaded boat, after the air-cases have been fitted, must not be less than that allowed by the rules in force when the boat was built, with the addition thereto of any correction that may have been made for camber or round of beam under these rules.

If the unloaded boats which have been placed in the water show signs of leakage, after floating for three hours, they must be treated in the manner described. In addition to the insertion of the air-cases, the hull must be made perfectly watertight.

The efficiency of the canvas topsides must be particularly noted during the survey as to whether they are watertight and of sufficient strength.

The very best materials are employed during the construction of these boats, and the workmanship must of necessity be the highest class.

Before construction is commenced detailed specifications and drawings must be submitted to the Board of Trade for approval, and after one set of boats is completed, severe tests must be undertaken and prove satisfactory before the construction of further boats of the particular design can be proceeded with.

These tests are very similar to those already fully explained in Part IV., Section E, when dealing with the open lifeboats of Class IIA, except that a further test is required to ascertain the efficiency of the scupper valves. They are as follows:

(a) Strength; (b) Freeboard; (c) Flotation (at least 3 hours to test watertightness of hull); (d) Deck-flooding; (e) Stability; (f) Seating and rowing.

PART V

SECTION A.-MOTOR BOATS

THE motor launch for use on board a vessel was for many years considered a luxury equipment, and confined to one or two leading shipping companies, but recent experience has proved the necessity of an extended supply not only for the purely passenger type of vessel, but also for the cargo-carrier.

The influence of the war, and the experience of many of our merchant seamen when cast adrift many miles from land, have naturally increased the demand for all foreign-going vessels, both cargo and passenger, to be equipped with at least one

motor lifeboat.

The Anchor-Brocklebank Steamship Co. have taken a very commendable action in providing accommodation, on most up-to-date lines, for a large number of cadets on several of their cargo vessels. These cadets are educated and take a share in the actual routine of the daily work and experience on board; they thus receive a training of the most practical and thorough character. Included in the equipment is a motor boat for the use of the cadets as a means of increasing their knowledge in seamanship. Messrs. Alfred Holt and Co. and other companies. carry power boats on several of their cargo vessels.

A large number of our Mercantile Marine officers have been attached to the Fleet Auxiliary vessels, on which motor boats are usually carried, and the very many advantages which have been experienced, and the speed with which the passage can be made from the vessel at the anchorage to the shore, have greatly increased the desire to have a power boat on board, as a part of the equipment.

Several countries now insist on the provision of at least one motor boat on foreign-going vessels.

The boat equipment of many of our large passenger liners includes one or two motor lifeboats or motor towing boats. The frontispiece indicates in the foreground a motor boat supplied to

the R.M.S. Aquitania by Messrs. Sir John Thornycroft and Co., Ltd. Even a cursory glance at the photograph will give one an

Wireless equipment of motor boat constructed by Messrs. Sir John Thorneycroft and Co., Ltd., Chiswick.

idea of the quality of construction, and Figs. 134-136 show the general arrangement of wireless equipment.

One very great advantage with this type of motor boat is, that in case of disaster, it can be utilised as a "mother

ship" for towing the ordinary pulling lifeboats and keeping them in touch with one another, and for the purpose of supplying them with medical comforts, blankets, etc., if required.

The installation of wireless telegraphy is an obvious advantage, and in the light of present-day experience, and the general advance in practical and scientific equipment, the dangers of an open sea passage are considerably reduced. The apparatus has a range of about 50 miles for transmitting and consequently would be able to keep in constant communication with steamers in the vicinity. The hull is built of teak or mahogany and fitted with a Thornycroft 4-cylinder motor of 30 B.H.P. starting on petrol and running on paraffin.

The speed under power only is about 7 knots, and the carrying weight of the boat in running condition, without passengers on board, about 51⁄2 tons.

The dimensions are: Length 30 ft.; breadth 9 ft. 6 ins. ; depth 4 ft. 6 ins.

Generally speaking the design is probably one of the best and most practical proposals to meet the difficulties experienced in life-saving at sea, and although it is not designed to comply with the Board of Trade requirements for a ship's lifeboat, the equipment is very efficient and complete.

Another design is shown in Figs. 137 and 138, which was constructed to meet all the Board of Trade requirements. Buoyancy air-cases are fitted in sufficient quantity to provide the reserve of buoyancy for the full number of persons carried and the weight of the motor and gear. The functions of this boat in addition to the larger space for the accommodation of persons, are practically the same as the boat previously referred to. It is fitted with a 15 B.H.P. motor, giving a speed of 6 knots. Two motor lifeboats as described were carried on the R.M.S. Britannic, which was lost during the war in the Mediterranean Sea.

The demand for power lifeboats during the past four years has been so great that to increase the usefulness and widen the radius of action of the ordinary pulling lifeboats, portable outboard motors have been fitted.

The United States authorities stipulate an outboard motor to be carried and attached to a lifeboat for towing purposes in case of necessity.

The writer has had some experience with the "Evinrude, the "Waterman Porto," and the "Simplex" outboard motors, the last-named being supplied by Messrs. W. Macmillan and Co.