*An elementary treatise on mechanics*(James McGlashan, Dublin, First edition 1844, Second edition 1847) and

*An elementary treatise on hydrostatics and hydrodynamics*(William Curry, Jun. and Co., Dublin, First edition 1846, Second edition 1850). We give below a version of the Prefaces of these two books:

**1. An elementary treatise on mechanics.**

**Preface.**

The application of the higher branches of mathematical analysis to the solution of mechanical problems has been so perfectly successful as to procure its universal adoption, not only in the treatment of abstruse and difficult questions, but also of the most simple and elementary parts of the science.

The effect of this has been to reduce the entire subject to an uniform system, but at the same time to place all parts of it alike beyond the reach of the student who is acquainted only with the elements of geometry.

The difficulty of finding a treatise on Mechanics free from this inconvenience has long been felt in the University of Dublin, and has been brought more immediately under the notice of the Author by his connection with the School of Engineering. In the hope of contributing to its removal, he has been induced to publish the following treatise, in which he has endeavoured, by means of simple geometrical constructions, to render the most important fundamental propositions easily understood by all classes of students.

In the Notes a brief outline is given of the method of applying to mechanical science the principles of Algebra, and of the Calculus; but the Author feels that it is unnecessary to dwell long on this application, as he could not hope to improve on the manner in which it has been already treated in Lloyd's *Mechanical Philosophy*, Venturoli's *Theory of Mechanics*, and Poisson *Traité de Mécanique*.

**2. An elementary treatise on hydrostatics and hydrodynamics.**

**Preface.**

The following pages are intended as a supplement to an *Elementary Treatise on Mechanics* by the same author, and the plan of that treatise has been followed, as far as possible, in giving easy geometrical proofs of the most important propositions concerning the Mechanics of Fluids. In this manner the fundamental propositions of Hydrostatics are demonstrated; but as this is the only part of the subject in which accurate results have been obtained, so it is the only part which appears capable of such simple and elementary demonstration. The theory of Hydrodynamics is too abstruse and difficult to be satisfactorily treated in a work of this nature; but since the principle of 'vis viva' (of which a brief account is given in the Appendix to the above-mentioned *Treatise on Mechanics*) furnishes not only the easiest and most direct solution of some of the most important cases of the motion of fluids, but also an immediate practical application of the theory to the investigation of the effects of machines, the author has ventured to deviate so far from his original design, as to give a brief outline of this practical me involves more of algebraic calculation than is quite consistent with the plan of the work.

For the sake of such students as are acquainted with the principles of the differential and integral calculus, an Appendix is added, containing the fundamental equations of Hydrostatics and Hydrodynamics, and their application to the first principles of the theory of sound.

The reader is requested to take notice that, for the convenience of students in the University, when ever mechanical propositions are quoted, reference is made to the *Elementary Treatise on Mechanics* which is already in their hands.