Another subject which is not compulsory, but which it is very necessary that the shipmaster should have more than a nodding acquaintance with, is ship construction. Studied in books, it looks formidable enough to any one but a student of the subject and an excellent mathematician; but a few visits to a shipbuilding yard intelligently made, and the things seen there carefully noted, would be of inestimable service. Allied to this is the vast subject of magnetism, which so intimately concerns every shipmaster in these days of steel, when the compass, poor thing, is hard put to it to remember the location of the magnetic pole at all, so sorely is it beset by diverting influences above, below, and around. But for a fair list of the things that all shipmasters _should_ know and might, from their abundance of leisure, in sailing ships especially, so pleasantly and easily acquire, reference should be made to a book which I remember as a bantling, but which has now grown to most portly proportions, "Wrinkles," by Squire T. S. Lecky. Within the boards of this splendid book Mr. Lecky has gathered a stupendous amount of information, which he imparts in the most delightful manner. For many years he commanded one of Messrs. Holt's steamships running between Liverpool and South America, so that his practical knowledge is as extensive as need be, while his theoretical learning is not only great, but sound. This book has been the hobby of his life; and it may truly be said that any shipmaster who will read, mark, learn, and inwardly digest it will be perfectly equipped for one of the most onerous of all professions if he only has the power of putting his learning to practical use. I have never seen, spoken to, or had a letter from Mr. Lecky in my life, so that what I say is perfectly unbiassed by any personal consideration. Mr. Lecky is a magnificent example of what the merchant shipmaster may make of his opportunities for study, if he be so inclined.