PREFACE.

THE following work is submitted to the Engineers and Mechanics of the United States by one of their number, who trusts that it will be found a convenient summary, for reference to Tables, Results and Rules connected with the discharge of their various duties.

The Tables comprising the Weights of Metals, Iron and Leaden Balls, Cast Iron and Copper Pipes, &c., were calculated expressly for this work, and from specific gravities of the different materials taken for the purpose.

The want of a work of this description in this country has long been felt, and this is peculiarly fitted to supply that want, in consequence of the adaptation of its rules to the metals, woods, and manufactures of the United States.

Having for many years experienced inconvenience for the want of a compilation of tables and rules by a Practical Mechanic, together with the total absence of units for the weights and strengths of American materials, I was induced to attempt the labour and the experiments necessary to furnish this work.

The proportions of the parts of the steam-engine and boilers will be found to differ in most instances materially from the English authorities; but as they are based upon. the actual results of the most successful experience, I do not hesitate to put them forth, being well assured that an adherence to them will ensure both success and satisfaction.

The principal sources of information from which I have compiled are Adcock, Grier, Gregory, the Library of Use

ful Knowledge, and the Ordnance Manual; and to the labours of the authors of these valuable works I freely acknowledge my indebtedness.

In my own efforts, I have been materially assisted by the officers of the West Point Foundry Association, who liberally furnished me with the means of making such experiments as were considered necessary; and to the Engineer of that establishment, Mr. B. H. Bartol, and also to Mr. Chas. W. Copeland, I am indebted for much valuable information and assistance.

To the Young Engineer I would say, cultivate a knowledge of physical laws, without which, eminence in his profession can never be securely attained; and if this volume should assist him in the attainment of so desirable a result, the object of the author will be fully accomplished

We have seen a proof copy of HASWELL'S Engineers' and Mechanics' Pocket Book, and approve of its design, which in extent exceeds that of any of its class: a work of this description has long been wanted, and we are satisfied of its usefulness and application.

GOUVERNEUR KEMBLE,
WILLIAM KEMBLE,
ROBERT P. Parrott,
B. H. BARTOL,

JAMES P. ALLAIRE,
B. R. M'ILVAINE,
HORATIO ALLEN,
C. E. DETMOLD,

CHARLES W. HACKLEY,

HOGG & DELAMATER,
STILLMAN & Co.,

T. F. SECOR & Co.,

BROWN & BELL,
SMITH & DIMON,

MERRICK & Towne,

December, 1843.

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West Point Foundry Association,
N. Y.

Allaire Works, N. Y.

} Civil Engineers, N. Y.

Professor of Mathematics, Colum bia College, N. Y.

Phenix Foundry, N. Y.

Novelty Works, N. Y.

Steam Engine Manufacturers,
N. Y.

Ship Builders, N. Y.

Southwark Foundry, Phila.

We concur in the above, having used a copy of Haswell's Engineers' and Mechanics' Pocket Book.

We take pleasure in adding our names to the list of recommendations of Haswell's Engineers' and Mechanics' Pocket Book, which we consider the best of the kind.

1. P. MORRIS & Co.,

Steam Engine _ Manufacturers,
Philadelphia, Penn.

With much pleasure we add our testimony to the value of Has well's Engineers' and Mechanics' Pocket Book, which we are gratified to learn is about to be published in a fifth edition, as each succeeding issue contains valuable additions to the preceding.

There are several valuable English works of this description, but the peculiarities and differences in this country render his a far more useful book; we consider it, in fact, an almost indispensable pocket companion.

MURRAY & Hazlehurst, Vulcan Works, Baltimore, Md.

We concur in recommending Haswell's Engineers' and Mechanics' Pocket Book, and consider it a very useful and valuable work. Steam Engine Manufacturers, Baltimore, Md.

A. & C. REEDER,

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In the daily use of Haswell's Engineers' and Mechanics' Pocket Book, we concur in the recommendation of it as one of very general reference and great utility; it is an indispensable pocket companion.

August, 1848.

REANEY, NEAFIE & Co., Penn Works, Kensington, Phila.