ONE:Handling and moving material is the principal matter to be considered in the arrangement of engineering works. The constructive manipulation can be watched, estimated, and faults detected by comparison, but handling, like the designs for machinery, is a more obscure matter, and may be greatly at fault without its defects being apparent to any but those who are highly skilled, and have had their attention especially directed [73] to the matter. TWO:The book has been prepared with a full knowledge of the fact, that what an apprentice may learn, as well as the time that is consumed in learning, are both measured by the personal interest felt in the subject studied, and that such a personal interest on the part of an apprentice is essential to permanent success as an engineer. A general dryness and want of interest must in this, as in all cases, be a characteristic of any writing devoted to mechanical subjects: some of the sections will be open to this charge, no doubt, especially in the first part of the book; but it is trusted that the good sense of the reader will prevent him from passing hurriedly over the first part, to see what is said, at the end, of casting, forging, and fitting, and will cause him to read it as it comes, which will in the end be best for the reader, and certainly but fair to the writer.