THEORETICAL NAVAL ARCHITECTURE: A TREATISE ON THE CALCULATIONS INVOLVED IN NAVAL DESIGN. BY SAMUEL J. P. THEARLE, Fellow of the Royal School of Naval Architecture; Member of the VOL. I.-TEXT. WITH THE PUBLISHERS COMPLIMENTS LONDON AND GLASGOW : PREFACE. THE favourable reception accorded to the Treatise on Practical Shipbuilding and Laying Off, which I had the honour of contributing to this Series three years ago, has encouraged me to venture upon the present work. The literature of Naval Architecture in the English language is not at all commensurate with the importance and magnitude of the shipbuilding industries of Great Britain, and that literature which exists is practically beyond the reach of most of those who desire and need acquaintance with it. Without particularising the special defects in this respect of existing books on the Theory of Naval Architecture, it may be said that either they are too large and costly, or written too obscurely to place them within the pecuniary or mental grasp of the majority of students, draughtsmen, and workmen. In preparing the present work, it has been my object to adapt it for the student who possesses simply a knowledge of elementary mathematics, and at the same time to provide for the requirements of those whose studies have been much more advanced. The former will find all the information necessary to enable him to perform the usual calculations of the drawing office, expressed in formulæ, or by rules easily applied; while the latter will be enabled, by following out the investigations by which these formulæ and rules have been obtained, to gather a tolerably clear idea of the principles upon which they are based. In offering this work to Naval Architects, it is hardly necessary for me to say that I have been indebted to those who have written before me for a large proportion of the ideas which it contains. It would, indeed, be impossible to write usefully upon a science which has been brought to its present state by the contributions of so many minds without being under such obligations. An effort has been made to simplify the problems involved in calculating the stability of ships by separating the calculations relating to the form of the vessel from those relating to her weight, and the position of her centre of gravity. A few alterations have been made in the usual nomenclature of the subject with a view to greater exactitude of expression. Some of these alterations were suggested by a recent writer in Naval Science. To what extent success, or the contrary, has attended my attempts to secure those very desirable objects-simplicity and accuracy, it will be for the reader to decide. At all events, it is hoped that a work based upon such a plan as the author himself would have desired when a student will be of service to the young naval architect by simplifying his studies, and to the draughtsman and shipbuilder by helping them in their daily duties. LONDON, February 1877. S. J. P. THEARLE, CONTENTS. PAGE Buoyancy-Stability-Hydrostatical Principles-Displacement -Areas of Plane_Surfaces-Trapezoidal Rule-Simpson's 1st Rule: Proofs-Fractional Intervals-Simpson's 2nd Rule -One-twelfth Rule-Worked Examples-Centre of Gravity of a Plane Area-Centres of Gravity of various Figures- Principle of Moments-Centre of Gravity of a Plane Area bounded by a Curve-Volumes of Solids-Volume of a Solid bounded by a Plane and a Curved Surface-Calculation of Displacement-Centres of Gravity of Solids-Centre of Gravity of a Volume bounded by a Curved Surface and a Plane-Curve of Areas of Midship Section-Of Sectional Areas-Of Tons per inch of Immersion-Of Displacement- Explanation of a Displacement Sheet-Geometrical Method Woolley's Rule--Proof-Centre of Buoyancy by Woolley's Rule-Geometrical Application of Wolley's Rule-Angular Measurement of Areas-Volumes and Moments of Wedge- |