INTRODUCTION.

In preparing a piece of work for letting, the duties of the Engineer are manifold. He must first of all have a clear conception of the thing to be done, and must give graphical expression to this idea, both by drawings and writing. It then becomes necessary to inform himself as to the probable cost of the proposed work, and if within reasonable limits, and he desire to let it, he must next notify contractors, and others, by such public announcements as will reach the largest number of reliable parties.

It is thus seen that the preparation of the drawings, estimates, specifications and advertisements are all duties of the Engineer, which he has heretofore been allowed to learn as necessity required, and often on the spur of the moment. But his duties do not end here; to insure the rapid and faithful execution of the work, he generally prepares the form of bid, with certain "instructions to bidders," giving restrictions with which they must comply to render their bids valid, and finally, to adopt a form of agreement which shall be approved by both parties to the

contract.

The duties of the contractor are simply to examine drawings and specifications, or the site of the work, present his bid, and, if successful, sign the contract and furnish the required securities. The construction of the work is foreign to the object of this book. These six steps are developed more fully in the corresponding chapters which follow.

PREFACE.

In the course of their professional career, Engineers are frequently called upon to prepare papers connected with the letting of work by contract. Often devoid of instruction, without experience and with no works of. reference at hand, it frequently happens that their efforts result in inconvenience and loss. Essential points are sometimes overlooked, and too great confidence is reposed in the good intentions of the parties. To aid in preventing such unfortunate results and to meet an acknowledged want in our schools for Engineers, the author has been induced to prepare this monograph on ENGINEERING, SPECIFICATIONS and CONTRACTS, and has aimed to make it equally useful as a text book and work of reference. An effort has been made to present clearly all the essential elements connected with the letting of work by

contract.

The several operations required have been systematically arranged, and the principles involved stated in their proper connections, and illustrated by a few typical forms carefully selected from the most reliable authorities.

To accomplish this object most effectively the entire operation has been divided into its six elements, as given under the headings to the several chapters.

It is not intended to make this work an exhaustive compendium of every possible form and condition, but to exhibit in the most concise manner the governing

principles in all operations between two or more parties. Hence a careful analysis of the several cases presented has been made, showing the items and essentials which should enter into ordinary contracts with the manner of uniting them to form a complete instrument. This analysis is rendered more apparent by the use of marginal references throughout the work and by a series of questions on the contents of each chapter.

Considerable difficulty was experienced in preparing the Code of Artisans' Rules for measuring work, since the little that exists in print on that subject is in such form as not to be generally applicable. The rules as given are the result of much correspondence and many interviews with experts. As prices for labor and materials are so variable no effort has been made to prepare lists, but an illustration is given of their use in the fifth section of the second chapter. For more complete information on this subject the inquirer is referred to the third volume of a work published by J. Haviland, in Philadelphia, 1829, entitled "The Builders' Assistant, including The House Carpenter's Book of Prices and Rules for Measuring and Valuing all their different kinds of Work" and also to the "Architects' and Builders' Companion:" Phila. 1875, by Frank W. Vogdes, Architect.

In the Engineering Specifications, Chapter III, cited as examples, much technical information is given which is not to be obtained from text books. It is therefore recommended that students should read them carefully, and for explanations of terms refer freely to the glossary specially prepared to accompany them. The questions

upon this chapter will be found very useful in a general review of the course.

To render the instruction as practical and interesting as possible, it has been the custom to require students at the University of Pennsylvania to perform all the operations for a special piece of work, such as the constructions of the model of a bridge, a tunnel, or other object, on a scale of about 1-24. Students should make the drawings, estimate quantities, and prepare bills of material, specifications, bids, and contracts. The bids may then be opened in presence of the section or class, and the work awarded to some member, selected as foreman to superintend its execution. It is not, however, necessary to carry the practice so far as the construction of models. Where facilities for such work do not exist it is recommended that the students be given special problems in constructions, as of a culvert, section of railway, either road bed or laying track, bridge or roof trusses to make estimates upon and prepare for letting. Such exercises prove very instructive, and compel an active interest in all collateral studies, by developing at once their practical applications. In conclusion the author gratefully acknowledges the information furnished by Genl. A. A. Humphreys, Chief of Engineers, U. S. A.; Col. Peter C. Haines, Secretary U. S. Light House Board; Genl. Wm, F. Raynolds, U. S. E. Engineer, Fourth Light District; Richd. K. Betz, and Jno. McClure, members of Carpenters' Company of Phila. and professional measurers; Messrs. Wilson Bros. & Co., Engineers and Architects; Hazel Wilson, C, E. Chief Eng. Penna. R.R.; Henry