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

in children habits of scientific reasoning. In this opinion he is sanctioned by the authority of Mr. Edgeworth. "Parents," says he, 66 are. anxious

"that children should be conversant with mechan❝ics, and with what are called the mechanical powers. Certainly no species of knowledge is "better suited to the taste and capacity of youth, " and yet it seldom forms a part of early instruc"tion. Every body talks of the lever, the wedge, “and the pully, but most people perceive that the "notions which they have of their respective uses

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are unsatisfactory and indistinct, and many en"deavour, at a late period of life, to acquire a "scientific and exact knowledge of the effects "that are produced by implements which are in

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every body's hands, or that are absolutely necessary in the daily occupations of mankind." Should these volumes be favourably received by the public, the Author proposes to pursue the same plan in four others, for which he has ample materials, and which will comprise Optics, Hydrostatics, Pneumatics, Chemistry, Electricity, and Magnetism*. He is aware that to persons conversant with these subjects, and who are accustomed to the arduous employment of education, hints for

These volumes have been published, and have all been sanctioned by the decided public approbation, having passed through several large editions.

the improvement of this work may occur; so far, therefore, from deprecating candid criticism, whether of a public or private nature, he will thankfully attend to every liberal suggestion that may be offered; and will, in the revision of these volumes, or in writing those that remain to the completion of his design, avail himself of every advantage with which he may be favoured.

The Author trusts that the whole work will be found a complete compendium of natural and experimental philosophy, not only adapted to the understandings of young people, but well calculated also to convey that kind of familiar instruction which is absolutely necessary, before a person can attend public lectures in these branches of science with advantage. "If," says Mr. Edgeworth speaking on this subject, "the lecturer does not "communicate much of that knowledge which he "endeavours to explain, it is not to be attributed "either to his want of skill, or to the insufficiency " of his apparatus, but to the novelty of the terms "which he is obliged to use. Ignorance of the 'language in which any science is taught, is an "insuperable bar to its being suddenly acquired; "besides a precise knowledge of the meaning of

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terms, we must have an instantaneous idea ex"cited in our minds whenever they are repeated; "and, as this can be acquired only by practice, it " is impossible that philosophical lectures can be

"of much service to those who are not familiarly acquainted with the technical language in which they are delivered.*"

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It is presumed that an attentive perusal of these dialogues, in which the principal and most common terms of science are carefully explained and illustrated, by a variety of familiar examples, will be the means of obviating this objection, with respect to persons who may be desirous of attending those public philosophical lectures to which the inhabitants of the metropolis have almost constant access.

* Mr. Edgeworth's chapter on Mechanics should be recommended to the attention of the reader, but the Author feels unwilling to refer to a part of a work, the whole of which deserves the careful pe rusal of all persons engaged in the education of youth.