FOR the benefit of those who may contemplate making use of this work, wholly or in part, it is well to lay before them at the outset a general statement of the plan upon which it is written, together with some advice for the use and study of the same, which may not properly belong under any of the several headings comprising the subject matter. A glance at the table of contents immediately preceding will give at once a clear idea of its scope and arrangement. From this it will be seen that the first five chapters are theoretical or educational in their nature, while the last chapter is devoted to practical work; and further, that the book does not presume upon any previous technical knowledge upon the part of the beginner, but aims to place before him in the preliminary chapters all that is necessary to a thorough understanding of the work performed in the last chapter, which constitutes the bulk of the book.

A very important feature of the work is the classification of the problems. The forms for which patterns may be required are divided, according to the methods employed in developing their surfaces, into three classes, and the problems relating to each are arranged in three corresponding sections of the last chapter, thus bringing near together those in which principles and methods are alike. In Chapter V (Principles Of Pattern Cutting) (Principles of Pattern Cutting) this classification is defined and the principles governing each class are explained and illustrated under three sub-headings of the chapter. The third subdivision treats of the method of developing the surfaces of irregular forms by Triangvlation, a subject not heretofore systematically treated in any work on pattern cutting.

A chapter on drawing (Chapter III (Linear Drawing)) has been prepared for the benefit of the pattern cutter especially interested in cornice work, and though he may not intend to become a finished architectural draftsman, this chapter will render him valuable assistance in reading the original drawings received from architects, from which he is required in many cases to make new drawings adapted to his own peculiar wants.

The New Metal Worker Pattern Book, besides being a systematic treatise on the principles of pattern cutting, is also valuable as a reference book of pattern problems and as a fund of information on the subject treated, to bedrawn from at convenience, and is so written that each problem, or chapter of descriptive matter, can be read independently of the others; so that the student whose time is limited can turn to any portion of the work the title of which promises the information sought, without feeling that he must read all that precedes it. The relative importance of the chapters depends, of course, upon the individual reader, and will be determined by what he considers his weakest points. However, it is advisable in the study of all works of a scientific nature to begin at the beginning and take everything in its course. If, therefore, the study of this work can be continued progressively from the first, much advantage will be gained.

The statement of each problem in prominent type appears at the head of the demonstration, and every problem is numbered, by which arrangemenl the problems are well separated from each other and easily found.

While each demonstration is considered complete in itself, some are necessarily carried farther into detail than others, and references are made from one problem to another, pointing out similarity of principle, where such comparison would be advantageous to one who is looking for principles rather than for individual solutions.

In preparing the diagrams used to illustrate the solutions of the problems, forms have been chosen which are as simple in outline as the ease will admit, upon the supposition that the reader will be able to make the application of the method described in connection with the same to his own especial case, which may embody more complicated forms. it must also be noted that, owing to the small scale to which the drawings in this work are necessarily made, extreme accuracy in the operations there performed is impossible. In many instances the length of the spaces used in dividing the profiles is much too great in proportion to the amount of curvature to insure accuracy. Therefore if apparent errors in measurements or results are found, they must not be considered the fault of the system taught. If such errors arc discovered the student is recommended to reconstruct the drawing upon his own drawing board in accordance with the demonstration given and to a scale sufficiently large to insure accurate results, before passing judgment.

In the preparation of this book, the former Metal Worker Pattern Book has been made the basis, to a certain extent, of the new work.* Such problems or portions of the former work as were found satisfactory have been assigned to their proper places in the new work without change. In the case of most of the problems, however, the demonstrations have been revised and the drawings accompanying them have been amended or corrected in accordance with the text, and in many cases entire new drawings have been made. To these have been added a large number of new problems based upon inquiries and solutions that have appeared in the columns of The Metal Worker since the former work was published. Much new explanatory matter not in the former work has also been added in the preliminary chapters, prominent among which are Chapter III (Linear Drawing), and the principles of Triangulation in Chapter V (Principles Of Pattern Cutting).

Especial care has been taken in the composition of the book to have each engraving and the text referring to it arranged, as far as possible, on the same page or upon facing pages, so as to obviate the necessity of turning the leaf in making references.

A great advantage is gained over the former work by the classification and numbering of the problems, which, in connection with the table of contents, renders any desired subject or problem easily found.

In regard to the system of reference tetters employed in the drawings, it should be said that the same letter has been used so far as possible to represent any given point in the several views or positions in which it may occur, the superior figure or exponent being changed in each view. To fully comprehend this the reader must carry in mind the concrete idea of the form under consideration, just as though he held in his hand a perfect completed model of the same, which he turned this way or that to obtain the several views given. Any point, therefore, which might on the model be marked by a letter A, would be designated in one of the views as A. while in other views or places where it might appear it would be designated as A'. A2, etc., or as A', A", etc. In the solution of problems by triangulation, dotted lines are alternated with solid lines, as lines of meas-urement, merely for the sake of distinction and to facilitate the work.

* Publisher's Note. - The author of this book, George W. Kittredge, prepared the drawings and outlined the demonstrations of all but a few of the less important problems in The Metal Worker Pattern Book, which was published in 1881, and also prepared portions of. the introductory chapters of that work.

Occasions arise in the experience of every pattern cutter wherein some portion of the work before him, of relatively small importance, is so situated that the development of its pattern by a strictly accurate method would involve more labor and time than would be justified by the value of the part wanted. It is the purpose of this work to teach the principles of pattern cutting, leaving the decision of such questions to the individual. Nevertheless, if one is thoroughly conversant with pattern cutting methods and familiar with pattern shapes it may be possible in such eases to obtain accurately the principal points of a required pattern and to complete the same by the eye with sufficient accuracy for all practical purposes.

As intimated above, some of the demonstrations are necessarily made more explicit than others. In the longer demonstrations and those occurring near the ends of the Sections, less important details of the work are sometimes omitted and certain parts of the operation arc only hinted at or are described in a general way. upon the supposition that the simpler problems in which the demonstrations arc carried further into detail would naturally be studied first.

Although the principles of pattern cutting here set forth may at times be regarded as somewhat intricate, it is believed that any one possessed of a fair degree of intelligence and application can easily master them.

Notwithstanding the great care which has been used in the preparation of this work, it is possible that errors may have found their way into its columns. Should errors be discovered by any of its readers, information of such will be gladly received.