LONDON:

Printed by A. & R. Spottiswoode,

New-Street-Square.

A NEW EDITION,

Considerably enlarged, and adapted to the improved State of Science,

BY THOMAS WEBSTER, SEC. G. S.

PRINTED FOR F. C AND

IN TWO VOLUMES.

VOL

LOND

PROPER

WITHDRAWN

YORK

BRARY

J. RIVINGTON, SCATCHERDA

NUNN;

LONGMAN, HURST, rees, ormE AND BROWN; T. CADELL; S. bagster;
J. BOOTH; J. BOOKER; J. MURRAY; J. RICHARDSON; BALDWIN,
CRADOCK AND JOY; BAYNES AND SON; J. HARDING; SHERWOOD,
NEELY AND JONES; G. AND W. B. WHITTAKER; T. TEGG; J. ROBINSON;
AND E. EDWARDS.

1822.

PREFACE

BY THE EDITOR.

THE HE original work by JOHN IMISON, entitled "The School of Arts," was some years ago put into the hands of the present editor, for the purpose of adapting it to the improved state of Philosophical Science. He engaged in the task the more readily, as he conceived that, by giving a general and concise view of the principles of Natural Philosophy and Chemistry, and of their application to the arts, he might be, in some degree, instrumental in promoting the diffusion of science among persons deprived of the advantages of a regular education.

Having had many opportunities, in the course of his profession, of observing the great use of even a small portion of scientific knowledge to a valuable class of the community, mechanics, he kept it particularly in his view to treat the various subjects, so as to render them as easily intelligible as possible; and, in general, to adapt the explanation of them to that class for which the work was intended by the original author.

In pursuance of this plan, the alterations from the original "School of Arts," and also the additions to it, became so considerable, that the work has assumed nearly the appearance of a new production; and some apology is perhaps due for altering the features of Imison's book so far, that it is no longer recognizeable. In this form it has passed through several editions, a circumstance that induces the hope, that the labour of the present editor has not been altogether useless.

In a book intended to exhibit only the popular elements of science, it would be in vain to expect much original matter. To draw from authentic sources, and to arrange and describe with clearness and precision the principal known facts, appears to be all that the nature of the undertaking admits of. The following work, therefore, is derived from the discoveries of others; but it will be found upon perusal, that in several instances, where the editor's profession or opportunities of observation enabled him to add any thing to the stock of particular knowledge, he has not failed to make the attempt.

With respect to the present edition, he has merely to notice, that a considerable part of it has been re-written; the whole has been revised; and every endeavour has been made to render it a source of entertainment and instruction to those who have not the opportunity of consulting more detailed treatises on the several subjects which are here considered.

T. W.