ART. I.-A Course of Lectures on Natural Philosophy, and the Mechanical Arts. By Thomas Young, M.D. For. Sec. R.S. F.L.S. Member of Emanuel College, Cambridge, and late Professor of Natural Philosophy in the Royal Institution of Great Britain. 2 Vols. 4to. 51. 5s. Johnson. 1807..

THE foundation of the Royal Institution we regard as an epoch which marks the progress of civilization in this great metropolis, and an happy omen of the general spirit of improvement, which pervades all ranks of the community. Among the middle ranks there has ever existed a sort of literary order. The university of Cambridge annually sends into society young men, many of them accomplished in the foundations of philosophical knowledge; at Edinburgh too the student has the advantage of the lectures of enlightened professors in the same branches of instruction; and we rejoice to hear that, latterly, Oxford has received a portion of the impulse communicated to the public mind, and has resolved no longer to confine the aspiring energies of the youthful mind within the narrow limits of verbal criticism and the dialectics of Aristotle. These fountains of knowledge, however pure, it must be confessed are by far too scanty to fertilize the immense tract of civilized society. In fact, the very name of philosopher is still regarded as denoting a sort of virtuoso, or an adept in occult sciences, wholly remote from the ordinary pursuits of life. This vulgar prejudice, the off spring of the darkness of superstitious ages, is wearing away apace. It is acknowledged that the human mind can have no employment more worthy of its exalted faculties, than the contemplation of nature, and the study of the laws which regu CRIT. REV. Vol. 12. September, 1807.. B

late the appearances of the wonderful scene which is cónstantly presented to our eyes; nor can the Creator receive a more pure homage, than the admiration irresistibly impressed on a thinking being by a rational and enlightened view of the harmony of his works. We regard the foundation of the Royal Institution as a public acknowledgment of this feeling among the most polished class of society, and giving it as it were a permanent and substantial existence among the establishments destined to form the manners of the rising generation.

Whether public lectures are the best modes of conveying the instruction, the diffusion of which is so much wanted, we have our doubts. We think that the elements, at least, of physical knowledge and the preliminary studies requisite for attaining them ought to form a regular part of common school learning. Boys of common capacities may have laid a solid foundation of classical knowledge at the age of 14. After that there are three or four of the most valuable years of life which are too often miserably thrown away. In these years the rudiments of geometry, algebra (as far as quadratic equations), the doctrine of ratios, and the easier parts of dynamics might be readily acquired, without any hindrance to a further proficiency in polite letters. It is the most childish ignorance to think that the capacities of boys are not equal to these studies. The deficiency is not in the pupil, but in the teachers. And till we see a thorough reformation in all our public schools, and an extension of school learning to the knowledge of things as well as of words, we must expect the study of sound and legitimate philosophy not to be greatly extended beyond the narrow circuit to which it is at present confined.

But till this desirable reformation has taken place, the reading of public lectures, aided by the illustration derived from experiment, is the best substitute for elementary education, and if those which are given at the Royal Institution do not afford to the hearers all the knowledge which they wish, they at least give the greatest possible aid to private study, and inform those to whom private study is too great a toil, of the great extent of their own ignorance. We cannot avoid premising these remarks to the splendid, extensive and profound work which is now before us. We had not the pleasure of being one of Dr. Young's auditors, and we have heard it asserted that his lectures were dry and uninteresting. We can readily understand how this must have been unavoidable. He must have been talking an unknown language to the great body of his audience. Having never received the elementary education which we have recommended, they were introduced suddenly into a new country,

in which they were ignorant of the language. To expect them to follow the sense of the lectures, is to require of a blind man, who has just received the faculty of seeing, to judge immediately of distances, shades, and proportions in the same manner as those who have from their infancy been blest with the use of their eyes. Though philosophy is not geometry, and perhaps many of the physical properties of matter and motion may be understood without the use of diagrams, still geometrical ideas are perpetually involved in these discussions, and those who are totally without them must be contented to remain in darkness, with regard to the greater part of the matters treated of. What is not understood or but half under. stood must necessarily seem dry and uninteresting, and per haps the more profound is the knowledge of the teacher, the less likely will he be to be attractive to a large and mixed assembly. Such an audience cannot raise themselves to the level of the lecturer, and the lecturer is unable to lower himself to the level of his audience.

Dr. Young has divided his lectures into three principal heads; Mechanics, Hydrodynamics, and Physics. The first head includes the laws of motion, and the doctrine of forces pressure and equilibrium; collision; the motions of connected bodies; statics; passive strength, and friction. The principles of the science are illustrated by their application to a great variety of the mechanical arts; nor do we know any work in which is compressed in a moderate compass so great a fund of information on these subjects. We must content ourselves with making a simple enumeration of the principal part of them. Besides the common mechanic' powers treated of in every system of mechanics, we have a lecture on drawing, writing and measuring; another on modelling, perspective, engraving and printing; one on architecture and carpentry; and one on time-keepers. In these and dispersed throughout the other lectures we find' explained the principles of drawing; outline; pen; pencil; chalks; crayons; Indian ink; water colours; body colours; miniatures; distemper; fresco; oil; encaustic painting; enamel; mosaic work; writing; polygraph; telegraph; geometrical instruments; pantograph; sector; theodolite; quadrant; vernier; levelling; modelling; casting; perspective; engraving; ruling; mezzotinto; etching; aqua tinta; musical characters; printing; walls; joints; mortar; arch; piers; domes; roofs; furniture; twisting; spinning; rope making; weaving; hats; paper; printing press; sugar mill; oil mill; wire drawing; glass-blowing; coining; stamping; sling; bow and arrow; whip; slitting-mill lathes; boring; mining, sawing; stone-cutting; grinding;

polishing; powder mills; threshing machines; corn mills kneading; levigating; bolt drawer; burning; blasting.

These are but a few of the processes, arts or instruments, which are modifications of the mechanical powers, and which are explained in the course of these lectures. We have not been very particular in the selection, and those which we have omitted are many of them of as much importance as those we have produced. Figures are given of all the instru ments and the machines at the end of the volume. Perhaps we have reason to complain that Dr. Young has been rather too copious than otherwise, in the objects of his illustrations; since in order, to prevent a large work becoming of still greater bulk, it has occasionally obliged him to adopt a brevity in his explanations, which is not always consistent with clearness.

The doctrine of forces acting upon solid bodies, and the application of them to purposes of practical utility, is the part of physical science which most readily admits of demonstration amounting very nearly to geometrical precision. To comprehend them thoroughly the use of diagrams seems absolutely necessary. But Dr. Young has thought right to dispense entirely with the use of diagrams in the body of his lectures,conteuting himself with referring to them at the end of his work; and giving short explanations of the diagram on the page opposite to the plate. But we think, though we do not disapprove of this method, where there is no obvious inconvenience, that Dr. Young has in several instances, for the sake of uniformity, adhered to it too pertinaciously. Where the object is very simple, it causes a useless repetition; where it is more complex, a redundance of words is necessary to prove what might have been done in half the compass, by the aid of a diagram, and with infinitely more clearness; and lastly, the circumstance of having dilated on the question under consideration in the lecture, has caused him to be so extremely concise in the references to the diagram, as to throw very little additional light on the subject. On the whole, then, we think the old method of referring at once to a diagram, where such reference aids the imagination, is the most useful, and that in so carefully avoiding it, Dr. Young has sacrificed both brevity and clearness to so close an adherence to systematic arrangement.

We have no disposition to dwell on these trifles, but to show that we are not hazarding random assertions, we will produce a very short specimen of his account of a very simple and useful little instrument, called a vernier, an instru ment which is in the hands of every body who is master of barometer. His words are these: