TO THE RIGHT REV. JAMES PRINCE LEE, D.D. LORD BISHOP OF MANCHESTER, THAN WHOM THERE IS NO MORE SINCERE FRIEND AND ADVOCATE OF EDUCATION IN ITS MOST COMPREHENSIVE AND ENLIGHTENED SENSE, THIS VOLUME IS INSCRIBED AS A MARK OF PERSONAL REGARD AND IN ACKNOWLEDGMENT OF THE EMINENT SERVICES HE HAS RENDERED TO THE EDUCATIONAL INSTITUTIONS OF HIS COUNTRY. 103269 IN BRINGING before the public the Fourth Edition of Useful Information for Engineers, which has been so favourably received by those for whom it was intended, I have added nothing new; I have only corrected a few errors which had escaped observation in the former Edition. In a short time I hope to issue a further volume of a similar character, which I trust may be worthy of its predecessors and meet with the same gratifying reception. W. F. MANCHESTER: September 15, 1864. PREFACE ΤΟ THE THIRD EDITION. IN ISSUING a Third Edition of my Lectures, after a period of four years from their first publication, I must repeat the expression of my gratification at the desire evinced by the members of the Engineering profession and others to avail themselves of such useful information as I have been able to obtain during a long and successful practice. I have only to add that in the present edition the reader will find the subject of boiler flues reconsidered, the results of my own experiments on collapse fully stated, and the rules for proportioning vessels to resist an external strain (of which in the first edition I could only lament our ignorance) given in a form in which they can be easily applied in practice. I hope in a second volume to give the entire detail of these experiments in full, which will lead, I believe, to new developments, and a much more intimate acquaintance with the subject. I have also added a caution as to the tables of the |