dom forms a part of early instruction. Every body talks of the lever, the wedge, and the pulley, but most people perceive that the notions which they have of their respective uses are unsatisfactory and indistinct, and many endeavour, at a late period of life, to acquire a scientific and exact knowledge of the effects that are produced by implements which are in 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 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

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

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 terms, we must have an instantaneous idea excited 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."*

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 perusal of all persons engaged in the education of youth.

CONVERSATION I.

INTRODUCTION.

FATHER-CHARLES-EMMA.

CHARLES. Father, you told sister Emma and me, that after we had finished the "Evenings at Home," you would explain to us some of the principles of natural philosophy: will you begin this morning?

Father. Yes, I am quite at leisure; and, I shall indeed at all times take a delight in communicating to you the elements of useful knowledge; and the more so in proportion to the desire which you have of collecting and storing those facts that may enable you to understand the operations of nature, as well as the works of ingenious artists. These, I trust, will lead you, insensibly, to admire the wisdom and goodness by means of which the whole system of the universe is constructed and supported.

Emma. But can philosophy be comprehended by children so young as we are? I thought that it had been the business of men, and of old men too.

Father. Philosophy is a word which in its original sense signifies only a love or desire of wisdom; and you will not allow that you and your brother are too young to wish for knowledge.

Emma. So far from it, that the more knowledge I get the better I seem to like it; and the number of new ideas which, with a little of your assistance, I have obtained from the "Evenings at Home," and the great pleasure which I have received from the perusal of these volumes, will, I am sure, excite me to read them again and again.

Father. You will find very little in the introductory parts of natural and experimental philosophy, that requires much more of your attention than many parts of that work with which you have been so delighted.

Charles. But in some books of natural philosophy, which I have occasionally looked into, a number of new and uncommon words have perplexed me; I have also seen references to figures by means of large letters and small, the use of which I did not comprehend.

Father. It is frequently a dangerous practice for young minds to dip into subjects before they are prepared, by some previous knowledge, to enter upon them; since it may create a distaste for the most interesting topics. Thus those books which you now read with so much pleasure would not have afforded you the smallest