SCIENTIFIC DIALOGUES,

INTENDED FOR THE

INSTRUCTION AND ENTERTAINMENT

OF

YOUNG PEOPLE:

IN WHICH

THE FIRST PRINCIPLES

OF

Natural and Experimental Philosophy

ARE FULLY EXPLAINED.

VOL. I.

OF MECHANICS.

"Conversation, with the habit of explaining the meaning of words
and the structure of common domestic implements to children, is
" the sure and effectual method of preparing the mind for the ac
quirement of science." Edgeworth's Practical Education.

BY THE REV. J. JOYCE.

NEW EDITION CORRECTED AND IMPROVED.

PHILADELPHIA:

PUBLISHED BY M. CAREY, 121, CHESNUT STREET.

A. Griggs K. Dickinson, Printers,-Whitehall,

GIFT

TO THE HONOURABLE

G163 J7 1815

CHARLES BANKS STANHOPE,*

AND TO THE HONOURABLE

JAMES HAMILTON STANHOPE.

GENTLEMEN,

I AM desirous of prefixing your names to these volumes in token of the affectionate attachment to which, from me, you are peculiarly entitled. And I am happy in the opportunity which this publication affords me of bringing to your recollection subjects, in the study of which you success

* This young man, the second son of the present Earl Stanhope, chose at an early period the profession of arms. In the year 1807 he was appointed aid-de-camp to General Moore, whom he accompa. nied to Sicily and Sweden. In the latter end of the year 1808, he was, as major, appointed to the command of the 50th regiment, then in Spain, at the head of which he was shot through the heart, at CoFunna, on the 16th of January, 1809.

PREFACE.

THE Author of these little volumes feels himself extremely happy in the opportunity which this publication affords him of acknowledging the obligations he is under to the authors of " Practical Education," for the pleasure and instruction which he has derived from that valuable work. To this he is solely indebted for the idea of writing on the subject of Natural Philosophy for the use of children. How far his plan corresponds with that suggested by Mr. Edgeworth in his chapter on Mechanics, must be left with a candid public to decide.

The Author conceives at least, he shall be justified in asserting, that no introduction to natural and experimental philosophy has been attempted in a method so familiar and easy as that which he now offers to the public:-none which appears to him so properly adapted to the capacities of young people of ten or eleven years of age, a period of life, which, from the Author's own experience, he is confident, is by no means too early to induce