The beneficial influence of Chriftianity is well illuftrated, in answer to those who urge against it the plea of its inefficacy. The Author then goes on to examine the objections that have - been raised to the divine authority of this religion from the incredibility of fome of its doctrines, particularly thofe concerning the Trinity, and atonement for fin by the fufferings and death of Chrift; the one contradicting all the principles of hu man reason, and the other all our ideas of divine juftice. To thefe objections I fhall only fay, that no argument founded on principles which we cannot comprehend, can poffibly difprove a propofition already proved on principles which we do not understand; and therefore that on this fubject they ought not to be attended to; that three Beings fhould be one Being, is a pro Epofition which certainly contradicts reafon, that is our reafon; but it does not from thence follow, that it cannot be true; for there are many propofitions which contradict our reafon, and yet are demonftrably true: one is the very firft principle of all religion, the being of a God; for that any thing should exift without a caufe, or that any thing fhould be the caufe of its own existence' (thefe expreffions however are far from being fynonymous) are propofitions equally contradictory to our reafon; yet one of them must be true, or nothing could ever have exifted.'

This fpecimen of our Author's metaphyfical reafoning is fufficient: he lays it down as a principle, that the Scripture-Trinity contradicts our reafon; and yet reafons about it. He might as well have faved himself the trouble, and advanced at once to his conclufion. Thefe,' referring to the doctrines above recited, confidered as declarations of facts only, neither contradict, nor are above the reach of human reafon. The first is a propofition as plain, as that three equilateral lines compofe one triangle; the other is as intelligible, as that one man should difcharge the debts of another.'

There is one paflage in that part of the book, where the Author illuftrates the wisdom and rectitude of the Chriftian difpenfation, which we cannot reconcile with the principles and general defign of this performance. He has told us, that the argument from the internal evidence' of Chriftianity is that, ⚫ which feems to carry with it the greatest degree of conviction;' and he compares it with thofe derived from prophecy and miracles this argument evidently arifes from the intrinfic reafonablenefs and excellence of the Chriftian doctrines and precepts: thus far we are agreed: But how muft we judge of the nature and tendency of Christianity? The answer is obvious, by reaReafon, fays this Writer, is undoubtedly our fureft guide in all matters, which lie within the narrow circle of her intelligence: on the fubject of revelation her province is only

to examine into its authority, and when that is once proved, fhe has no more to do but to acquiefce in its doctrines, and therefore is never fo ill employed, as when the pretends to accommodate them to her own ideas of rectitude and truth." This appears to us as a very unguarded and dangerous pofition; it precludes and difcourages all rational inquiry, and, if purfued, will justify the wildeft enthufiafm or fuperftition.

Our Author concludes the argument with this general obfervation, that if a divine revelation, all circumstances confidered, ' was in every part familiar to our understandings, and confo. nant to our reason, we should have great cause to fufpect its divine authority; and therefore, had this revelation been lefs incomprehenfible, it would certainly have been more incredible.'

The perufal of this book, we freely confess, excited at first fome fulpicions and apprehenfions as to its general tendency but they were obviated by the main tenour of the Author's argument, and by the explicit and ingenuous account he gives of his own fituation towards the conclufion: we are perfuaded that he is fincere in his profeffions; and we join with him in expreffing our wishes that the purpose of this work may be an(wered. Had the arguments (he fays) herein ufed, and the new hints here flung out, been more largely difcuffed, it might eafily have been extended to a more confiderable bulk; but then the bufy would not have had leisure, nor the idle inclination to have read it. Should it ever have the honour to be admitted into fuch good company, they will immediately, I know, determine, that it must be the work of some enthusiast or Methodist, fome beggar, or fome madman. I fhall therefore beg leave to affure them, that the Author is very far removed from all these characters: that he once perhaps believed as little as themselves; but having fome leifure, and more curiosity, he employed them both in refolving a question which feemed to him of fome importance,-whether Chriftianity was really an imposture founded on an abfurd, incredible, and obfolete fable, as many fuppofe it? or whether it is, what it pretends to be, a revelation communicated to mankind by the interpofition of fupernatural power? On a candid inquiry he foon found, that the first was an abfolute impoffibility, and that its pretenfions to the latter were founded on the moft folid grounds. In the further pursuit of his examination, he perceived, at every step, new lights arifing, and fome of the brightest from parts of it the moft obfcure, but productive of the clearest proofs, because equally beyond the power of human artifice to invent, and human reafon to discover. These arguments, which have convinced him of the divine origin of this religion, he has here put together in as clear and concife a manner as he was able, thinking they might have the fame effect upon others, and being of opinion,

opinion, that if there were a few more true Chriftians in the world, it would be beneficial to themselves, and by no means detrimental to the Public.'

ART. VIII. The Art of Drawing in Perspective made easy to those who have no previous Knowledge of the Mathematics. By James Fergufon, F. R. S. Illuftrated with Plates. 8vo. 3. 6 d. Cadell

1775.

WE

E are glad to find that our Author, no lefs induftrious than ingenious, is still able, notwithstanding his inhrm ftate of health, to amufe himfelf' in a way fo acceptable to the Public-as in ftudying and preparing the contents of this treatise and we hope that he will long continue to amufe himfelf in the fame way. As there are many whose business or recreation requires fome knowledge of the rules and practice of perspective, who have neither leifure nor inclination for a courfe of previous mathematics, a compendium of this kind was much wanted, and, we may venture to fay, will be very acceptable and ufeful. The rules here laid down are concife and clear; and yet they may be applied to most common cafes that can occur. The drawings are fo neat and elegant, that a perfon of the least attention must be able to underftand them. The : neceffity of this art will be readily allowed by all who know any thing of that which painters call keeping, i. e. " representing objects in the fame manner that they appear to the eye, at different diftances from it.' We fhall tranfcribe what our Author fays on this head in his preface. Every man is fenfible, that, if he should ftand by the fea-fide, and look at a boat with men in it at some distance, he could not diftinctly fee the features of thofe men, much lefs the wrinkles and marks of the mufcles in their faces or bare arms. And if he were in a boat, at fome distance from the land, he could not perceive the eyes and beaks of fowls on the fhore. Yet fo it is, in one of the famous cartons of Raphael, representing the miraculous draught of fishes, that men in each of the two boats appear of full size, the fea tures of their faces ftrongly marked; and the boats are reprefented fo fmall, and the men fo big; that any one of them appears fufficient to fink either of the boats by his own bare weight: and the fowls on the shore are likewife drawn fo big, as to seem very near the eye of the obferver; who could not poffibly, in that cafe, diftinguish the features of the men in the diftant boats. Or, fuppofing the obferver to be in either of the boats, he could not see the eyes or beaks of the fowls on the shore.'

Another inftance is of a very capital miftake in Raphael's historical picture of our Saviour's transfiguration on the Mount, where he is reprefented with thofe who were then with him, almost as large as the reft of his difciples at the foot of the REV. June 1776.

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Mount,

Mount, with the father and mother of the boy whom they brought to be cured: and the mother, though on her knees, is more than half as tall as the Mount is high; so that the Mount appears only of the size of a little hay-rick, with a few people on its top, and a greater number at its bottom on the ground: in which cafe, a fpectator at a little diftance could as well diftinguish the features of thofe on the top as of thofe on the ground. But upon any large eminence, deferving the name of a Mount, that would be quite impoffible.-My only reafon for mentioning thefe extraordinary particulars, is to fhew how neceffary it is for painters to be well acquainted with the rules of perspective.'

In the last chapter the Author has defcribed a machine, by which any person may delineate the true perfpective figures of objects, without having learned any of the rules. He tells us that he is indebted for the firft fketch of it to the late Dr. Bevis, and believes that he was the inventor of it, although he never made it public. The ground plane of this inftrument is an oblong fquare board, to which another moveable piece is fixed by means of two hinges. This moveable part consists of two arches or portions of circles joined together at the top and at bottom to a cross bar as long as the plane on which it refts is broad. One part of each hinge is fixed to this bar, and the other part to a flat board half the length of the lower or bafe plane, and glued to its uppermoft fide. There is a fliding piece (much like the nut of a quadrant of altitude belonging to a common globe) on the outer fide of one arch, which may be I moved any where between its extremes; and there is fuch another flider adapted in like manner to the other arch. The centre of either arch is at the lower extreme of the other, where they are joined to the cross bar; and two-threads are ftretched tight, one from the centre of one arch to its flider, and the other thread to the flider on the other arch from its centre: the ends of the threads are faftened to the centres and fliders. By moving the fliders, the interfection of the threads may be brought to any point of the open space within the arches. In the middle part of the board to which this moveable apparatus is fastened by means of the two hinges, there is a groove, to which is adapted a fliding bar, that may be moved farther out or farther in, at pleasure: at the outer end of this bar is fixed an upright piece, in which is a groove for receiving a flider. In this flider is a fmall hole for the eye to look through, when the machine is ufed; and a long flit in the upright piece, fo that the hole may be feen through when the eye is placed behind it, at any height of the eye above the level of the horizontal bar.

In delineating any object by means of this machine, it must be fixed to a table with the apparatus laft defcribed from the object; fo that the circular arches being raised perpendicular to the plane, the space between them may lie between the eye and the object. A fquare piece of paper is to be fixed on the furface of that half of the board which is nearest the object. Look through the hole in the upright piece to any point in the object to be delineated, and move the fliders on the arches till the interfection of the threads is directly between your eye and that point; then lay the arches flat on the paper, and mark the interfection of the threads upon it. Proceed in the fame manner to determine the fituation of every other point on the horizontal paper; join thefe points by ftraight lines, and you will have the outlines of the propofed object: fhade the whole, making the lights and fhades as you fee them on the object it felf, and you will have a true perspective figure of it. The arches fhould be at least a foot wide at bottom, and the eye should then be at least 10 inches from the interfection of the threads, when the arch is fet upright.

If a pane of glass, laid over with gum water, be fixed into the arch, and fet upright when dry, a perfon who looks through the hole may delineate the objects upon the glafs which he fees at a diftance through and beyond it, and then transfer the delineation to a paper put upon the glass.'

ART. IX. An Account of fome German Volcanos, and their Productions. With a new Hypothetis of the prifmatical Bafaltes; established upon Facts. Being an Effay on phyfical Geography for Philofophers and Miners. Publifhed as fupplementary to Sir William Hamilton's Obfervations on the Italian Volcanos. By R. E. Raspe. 8vo. 3 s. 6d. Boards. Davies. 1776.

T

HE nature and various effects and appearances of volcanos, conftitute a branch of natural hiftory that hath, till very lately, been little attended to. Even the knowledge that fuch phenomena had ever appeared in many parts of the earth where they have, in fact, been moft frequent, may be regarded as a new revelation to the philofophic world. The examination of thefe wonderful objects is, however, well worthy of our earnest purfuit; and Mr. Rafpe's performance will be no unufeful guide to the curious investigator.

Our Author has prefaced his work by the following advertisement :

Many philofophers having of late made ufe of volcanos and earthquakes as undoubted active principles to explain the inequalities of the earth, it is matter of juft furprize why the various nature of volcanos and their productions fhould be fo long neglected. The Author therefore confidered the following facts

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