A special feature of the book is the series of curves on plates VI, VII. VIII and IX. For determining the proportions of sailing yachts of various sizes. These have been prepared by the writer from data on a large num ber of yachts. And should prove of great assistance in roughing out a de sign. The methods presented for determining stability have been selected with reference to their applicability to small work, and are not ordinarily to be found in works on naval architecture. The various operations involved in designing a sailing yacht are i1 lustrated in the text by work on the thirty-foot water line sloop whose plans are given on plates I. II, III and IV This is intended to be a conventional rather than an ideal design, and was chosen on account of its suitability for purposes of illustration. The complete data on this design is given in the appendix. The author is indebted to Prof. C. H. Peabody. Of the Massachusetts Institute of Technology, for criticism and suggestion.