PREFACE

of practice, and a knowledge of these can only be acquired by rrequent
reference and repetition, hence the reason why some of the information
is conveyed in the form of Questions and Answers.

We have drawn largely on the experience of others as their
knowledge has enabled us to collate the varied information which forms
the basis of the Board of Trade Oral Examinations for Certificates of
Competency as Second Mates, Mates and Masters.

I am indebted to numerous friends and colleagues for advice and
guidance in the preparation of this work and gratefully acknowledge
their assistance, also the kindness of many firms in granting permission
to reproduce illustrations from their publications, and particularly to
Mr. William M. Gray, B.Sc., M.I.N.A., for criticism and many of the
drawings which illustrate the chapter on Ship Construction, also to—
Messrs. Allan Whyte & Co., Glasgow Wire Hope Manufacturers.
Brassey's Naval Annual.
The British Mannesmann Tube Co., London. Derricks.
Messrs. Brown, Lennox & Co., London. Anchors, Cables and
Buoys.
Messrs. Bruntons (Musselburgh), Ltd., Musselburgh Wire Ropes.
Messrs. The Bergius Co., Ltd., Glasgow. Kelvin Motor Engines.
Messrs. Chadburn's (Ship) Telegraph Co., Ltd., Liverpool. Ship
Telegraphs,
Messrs. Davey & Co., London. Blocks and Tackles.
The Electric Submerged Log Co., London.
Messrs. Emerson, Walker Jitd., Gateshead-on-Tyne^ Steani
Capstans and Windlasses.
Messrs. Haslam & Kewton, Ltd., Derby. Refrigerating Plant.
Messrs. Henry Hughes & Son, Ltd., London. Echo Sounding
Machines.
Messrs. John Hastie & Co., Greenock. Steering Engines.
Imperial Merchant Service Guild, IforxesVs Jury Rudder*
Radio Communication Co.^Ltd^ Ijondon. Direction Finders
Messrs. Kelvin, Bottojnley & Baird, Ltd., Glasgow;. Soundiag
Machines* Pneumercator Tank and Draught Gaugea*