of the present day before attempting to appreciate the many successful and unsuccessful attempts of early inventors. The remainder of the book is chiefly descriptive, and, since the space at my disposal was necessarily limited, I have confined my remarks and diagrams, for the most part, to an explanation of the general construction and details of one good modern compound marine engine and boiler.
The book, as a whole, forms an easy introduction to my larger and more advanced Text Book on Steam and Steam Engines, issued by the same publishers. It may be thoroughly discussed in the minimum number of lectures demanded by the Science and Art Department, if the student systematically works out at home a few of the Questions given at the end of each Lecture, and hands them to his teacher for correction. This system of combining short lectures with numerous examples and sketches to be worked out by the student at home, produces the most satisfactory results.
I have been much indebted to Reed's excellent Engineer's Handbook to the Local Marine Board Examinations for Certificates of Competency as First and Second-class Engineers, and to Mr. Somerscales' Collection of Questions on the Steam Engine, for hints as to the treatment of the first three Lectures and some of the examples throughout the book. I have also to express my obligations to Mr. Middleton, Teacher, Orkney, who kindly examined the manuscript of the part on Mensuration; and also to Mr. Wm. C. Borrowman, Wh.Sch., who has assisted me in revising most of the proofs.
If any errors should be observed by readers, or answers obtained to unanswered arithmetical questions, I shall feel much obliged for an early note of them, and I shall also gratefully acknowledge the receipt of any suggestions or communications tending to increase the usefulness of the work, as my desire is, as far as possible, to keep it abreast of the times.
THE GLASGOW AND WEST OF SCOTLAND
TECHNICAL COLLEGE,
September 1888.