ing is superior to any elementary treatise on Mechanics at present in use in this country. The small work of Dr. Wood is the only one which can be put in competition with it; and of this it is to be remarked, that its plan is professedly more contracted than that of Mr. W.'s treatise. As far as it goes, it is deservedly held in the highest esteem as a clear and solid introduction to the science; but the student who is desirous of following up the subject to such an extent as shall introduce him to the modern researches on various points connected with this important branch of natural philosophy, and especially if his views should extend to an acquaintance with physical astronomy, must seek for further iuformation than the mere elements can give him. He must familiarize himself with the refinements which modern analysis has introduced into the higher investigations concerning mechanical forces. In order to attain such views of the subject, he has hitherto had no resource but the treatises of the French philosophers. The author of the works now before us has ably supplied the deficiency; and has afforded the means of conveying the student step by step from -the most elementary ideas, up to the most recondite investigations of the science of force and motion.

The treatise on Dynamics was originally designed as a second volume, but subsequently has been made a separate work, and such in fact it is. We think the student ought to have the distinction clearly before him, for unquestionably the science of Dynamics cannot with any propriety be classed under the same head, or under the same common name with that of Mechanics, properly so called. The laws of physical forces, and the motions of bodies acted upon by them, are in their very nature and principle essentially distinct from those involving only the composition and resolution of the force of impact and of pressure; and the powers produced by the resistance of an inflexible body to a force applied to some part of it, and thus communicated to other parts; which in fact are the primary principles of those powers properly called mechanical. Mr. Whewell, in improving upon existing English systems of Mechanics, by adopting much from the French writers, has also in his turn supplied some deficiencies in those writers, which appear of no small importance. He has pointed out with great acuteness, that while they display the utmost ingenuity and refinement in their investigations of many of the more recondite parts of the science, they have built on a defective foundation, in not having rigidly demonstrated some of their first principles. It is, indeed, well known that some of the

first and most elementary truths of mechanics are precisely those which it is most difficult to demonstrate. Nothing of course can be more essensial to an elementary treatise, than that those first principles should be all laid down with clearness and precision, both in statement and proof; and we think this is most completely and satisfactorily done in Mr. W.'s work. He has consulted very much the convenience of the student in so arranging his subject, that for understanding all the earlier parts, comprizing the fundamental propositions in statics, no further knowledge of mathematics is required than the elements of geometry, algebra and trigonometry. In the remaining portion a more perfectly analytical style is adopted; and the higher parts of trigonometry, algebra, and the differential calculus, are supposed to be understood.

What we have now mentioned will be sufficient to convey an idea of the nature and character of these works; and we do not conceive it would be of any use to give a list of the contents. We shall therefore merely proceed to a few similar remarks on the design of the other work before us.

With respect to its general plan and character, a very short statement will suffice, as from its nature we cannot enter into any details.

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The term Hydrostatics is here employed in its comprehensive sense, to signify both the science of non-elastic fluids, with regard to equilibrium, and that which relates to their forces and motion, which has been sometimes colled Hydrodynamics, as also the investigation of the mechanical perties of elastic fluids, otherwise termed pneumatics. To the different subdivisions of each of these subjects, the author's attention is successively directed. The two first sections comprize a very clear explanation of the fundamental principles of the science of fluids, in which we think the learner will neither have to complain of the brevity found in some treatises, nor of the prolix perplexity of others. These general principles lead immediately to the subject of specific gravities. And thence the author proceeds to that most essential branch, the pressure of fluids; this in fact may be justly called the key to the whole science, since it involves the peculiar principle which essentially distinguish fluids from solids, and which renders their action so peculiar, and in some cases apparently so paradoxical. The motion of fluids and the theory of resistances, are the next topics of inquiry; and the last division of the work contains a most able elucidation of the subject of elastic fluids, which is sometimes made to form a distinct science under the name of

Pneumatics. Here the author discusses the expansion of bodies by heat, the theory of the thermometer and barometer, with the application of the latter to the measurement of heights. The theory of pumps is clearly given, and the treatise closes with the very curious and interesting phenomena of capillary action.

The authors of both treatises have taken care to introduce in every part a sufficient supply of problems and examples, which unquestionably form one of the most essential features in any elementary work; by these not only are the truths of the science fixed in the memory of the student, in a manner more indelible than could be effected by any direct instruction alone however excellent, but also by the exercise given to the inventive and reflective powers in the solution of these questions, what is really the principal end of scientific education is promoted and secured.

ART. VIII.—1. The Book of the Roman Catholic Church; in a Series of Letters addressed to Rob' Southey, Esq. LL.D. on his "Book of the Church." By Charles Butler, Esq. Murray. 8vo. pp. 347. 9s. 6d. 1825.

-Strictures on the Poet Laureate's" Book of the Church." By John Merlin. Second Edition. London, Keating & Brown; Dublin, R. Coyne. 8vo. pp. 93. 1824. 3.-An Inquiry into the Nature, Object, and Obligations of the Religion of Christ; with a Comparison of the Ancient and Modern Christianity of England; in Reply to the Archdeacon of Sarum's" Protestant's Companion:" in a Fourth Letter to the Archdeacon of Bath. By the Rt. Rev. Peter Augustine Baines, D. D. London, Keating & Brown; Bath, Gye. 8vo. pp. 96. 3s.

WE were confident that Mr. Southey's Book of the Church would do much good; but the result has exceeded our expectations. The Roman Catholics, perceiving that it opposes a new obstacle to their success, have endeavoured, by every expedient, to remove it out of their way. Dissenters,. while they feel grateful for anti-catholic aid, smart under the lash of the new historian of the church; and infidels, who shake hands with superstition and fanaticism, and reserve their venom for genuine Christianity, have assailed the historian in the Westminster Review, with an insolence and injustice which defeat their own object. It is evident, therefore, that Mr. Southey's book tells. Adversaries may detect

and exaggerate its faults; lukewarm friends may refuse to pardon them; but the public sentence is pronounced; and neither Dr. Milner, nor Dr. Baines, neither Mr. Butler, nor Mr. Bentham, can procure a reversal of the decree.

Political circumstances have increased the importance of the work. The Roman Catholics, on the point of making an unusual effort, intended to rest their controversial engines upon Lingard's account of the Reformation. They thought that the bold assertions of a Jesuit, backed by an appeal to the writings of his predecessors, and re-echoed by notorious unbelievers, would induce the people of England to forget the history of past ages. They intended, with the assistance of the redoubtable Mr. Cobbett, to convince the world that the Reformation was a curse. They resolved at all events to show, that other churches were as mischievous as the church of Rome, and thus to risque our common christianity out of affection for the representation of St. Peter.

The success of these machinations was defeated by the Book of the Church. A popular writer summoned us to reconsider the ecclesiastical history of our country, described the introduction and growth of true religion; pointed out the corruptions which were suffered to deform it, proved, that in spite of particular exceptions, the general result was immensely in favour of Christianity; and lastly, painted the cruelties of expiring Popery, and the frenzy of triumphant Puritanism with an eloquence that excited universal admiration, and a pathos which found its way to every heart. In the glowing narrative of Mr. Southey, the church appeared in her real character, observing the just mean between superstition and fanaticism on the one hand, and a latitudinarian infidelity on the other. Neither a despot nor a democrat, neither a socinian nor a methodist, no friend to field preaching, and no friend to friars, the Protestant episcopal church submitted itself to the examination of every inquirer, asked to be judged by its merits, rallied its supporters and children round a Parent to whom they were so deeply indebted; and if it exasperated a few desperate enemies, took from them at the same time half their power of doing mischief.

Such being the actual state of things as relates to Mr. Southey's history, it is worth while to observe the answers with which he has been favoured. Two out of the three works now before us are direct and avowed replies to the Book of the Church; the third relates to a similar subject, and is necessary to complete our view of existing Roman Catholic tactics. The whole form a curious specimen of the unanimity of the infallible church; agreeing with one another

in dislike to the Reformation, and in no other particular whatsoever.

Mr. Butler, the best known, the wisest, and by far the most formidable, may be presumed to speak the language of the Catholic laity; and it is a gentlemanlike and moderate phraseology. Merlin, alias Dr. Milner (we should have been sorry if the anagram of the vicar apostolic had proved him to be no conjuror), represents the bigoted popish priesthood, and proves that the spirit of that body is unchanged. While Bishop Baines may afford amusement by his blunders, but not having been thanked by the Catholic Association, must be considered as a coadjutor with whom that body could dispense.

"No person," says Mr. Butler, in his dedication, "admires more than I do the golden sentence of St. Francis of Sales, that a good Christian is never outdone in good manners. "In fact, Mr. Butler admires the sentence so much that he quotes it, gilding and all, first to Mr. Blundell, his dedicatee, and secondly to Dr. Southey, in the introductory letter. The letter also informs us, that in the controversy between Catholics and Protestants there should be " equal wish to soothe, to conciliate, to find the real points of difference very few, and to render them still fewer, and an equal unwillingness on each side to say or to write any thing unpleasing to the feelings of the other." This is good advice; and we recommend it to the attention of Bishops Milner and Baines. The former commences his Strictures' in the following words :

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"A degree of enthusiasm is requisite to constitute the character of a Poet; but no quality is more at variance with it than religious fanaticism. This confuses the imagination, misleads the judgment, and hardens the heart; in so much that a man of real genius and talents for the Muses, on falling into this fanaticism, would be found too dull in his compositions to gain for them a patient reading. Such have been the late aberrations of our Laureate's mind. After writing D'Esperilla's Letters in commendation of the Catholic religion, and Wat Tyler's Drama, to excite popular tumults against government, he has latterly celebrated and recommended the chief and most dangerous schismatics from the establishment, the Wesleys, Whitfields, and their associates; and now, in the frantic style, and with the lying memorials of another such schismatic, John Fox, he raves through the history of many centuries, in abusing and calumniating the common source of Christianity, iu order to court the heads of the present establishment, under pretence of vindicating it. "Mr. Southey, it has been stated, is a Poet; that is, as the original Greek word signifies, a maker or inventor." P. 3.

This must be very soothing to Mr. Southey. He has a

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