racter, furnished by Mr. Jeffery, the editor of the Edinburgh Review, As this writer, however, is avowedly no competent judge of the works of the Professor, his remarks, as far as they are literary, respect rather the manner of composition and the qualities of style which distinguished Mr. P., than the subjects themselves which engaged his powerful mind : and thus, whilst we admire the eloquence and the affectionate regard which animate this biographical outline, we desiderate, on the part of the author, the scientific knowledge which was ne. cessary to place in a proper light the attainments and performances of his deceased friend. 'Mr. Playfair, we are told, wrote slowly, his first sketches being usually very slight and imperfect, like the rude chalking of a masterly picture. His chief art and great pleasure was in their revisal and correction : and there was no liinits to the improvement which resulted from this application.

As he never wrote upon any subject of which he was not perfectly master, he was secure against all blunders in the substance of what he had to say; and felt quite assured that if he was only allowed time enough, he should finally come to say it in the very best way of which he was capable. He had no anxiety, therefore, either in undertaking or proceeding with his tasks; and intermitted and resumed them at his convenience with the comfortable certainty that all the time he bestowed on them was turned to good account, and that what was left imperfect at one sitting might be finished with equal ease and advantage at another. Being thus perfectly sure, both of his end and his means, he experienced, in the course of his compositions, none of that little fever of the spirits with which that operation is so apt to be accompanied. He had no capricious visitings of fancy which it was necessary to fix on the spot or to lose for ever-no casual inspirations to invoke and wait for--no transitory and evanescent lights to catch before they faded. All that was in his mind was subject to his control and amenable to his call, though it might not obey at the moment; and wbile his taste was so sure that he was in no danger of over-working any thing that he had designed, all his thoughts and sentiments had that unity and congruity that they fell almost spontaneously into harmony and order; and the last added, incorporated, and assimilated with the first as if they bad sprang simultaneously from the same happy conception."

There can be no doubt that the style of Professor Playfair was extremely well adapted to scientific discussions. It was clear, natural, and unburdened with unnecessary ornament. Having, on all occasions, a distinct conception of what he meant to say, he used the exact number of words requisite to convey his meaning; and never added a trifling thought, or even repeated an important one, merely to give his sentences the full turn and sonorous termination which, in the opinion of some of his countrymen, seem indispensable to fine writing, Most Scotchmen write English as if it were to them a foreign language; and thus, however well they may succeed in historical or scientific composition, they never become masters of those graces and felicities of style which arise from the successful application of the more idiomatic arrangement of words and phrases, to which the ear of his southern neighbour is accustomed from his infancy. In grave and solemn performances, it will be admitted, a certaiu departure from the colloquial forms of speech is attended with considerable advantage; and in the departments of theology, for example, as well as in all the higher branches of science, we are war

Ved in allowing, and even in encouraging, the distinction between ken language and a written language. In proportion, then, as

composition is permitted to differ from the ease of conversa tion and the freedom of oratory, excellence in it will be more within the reach of those who study our language in books, and write it according to grammatical rules: and there is no doubt that it is on this very account such authors as Mr. Playfair become a sort of model for an elegant philosophical style, intelligible alike to the native Engglishman and to the learned foreigner. The “ Illustrations of the Huttonian Theory" have been universally admired as a specimen of fine composition on a philosophical subject. Even the Wernerians, who question the principles and abjure the conclusions of that ingenious treatise, acknowledge it to be a beautiful and most fascinating geological romance.

“But,” says Mr. Jeffery, “we need dwell no longer on qualities that may be gathered hereafter from the works he has left behind him. Those who lived with him mourn the most for those which will be traced in no such memorial; and prize, far above those talents which gave him his high name in philosophy, that personal character which endeared him to his friends, and shed a grace and a dignity over all the society in which he moved. The same admirable taste which is conspicuous in his writings, or rather the higher principles from which that taste was but an emanation, spread a similar charm over his whole life and conversation; and gave to the most learned philosopher of his day the manners and deportment of the most perfect gentleman. Nor was this in him the result merely of good sense and of good temper, assisted by an early familiarity with good company, and a consequent knowledge of his own place and that of all around him. His good breeding was of a higher descent, and his powers of pleasing rested on something better than mere companionable qualities. With the greatest kind. ness and generosity of nature he united the most manly firmness and the highest principles of honour,—and the most cheerful and social dispositions with the gen. tlest and steadiest affections. Towards women he had always the most chivalrous feelings of regard and attention, and was, beyond almost all men, acceptable and agreeable in their society, though without the levity or pretension unbecoming his age or condition. And such, indeed, was the fascination of the most perfect simplicity and mildness of his manners, that the same tone and deportment seemed equally appropriate to all societies, and enabled him to delight the young and the gay with the same sort of conversation which enabled him to instruct the learned and the grave. There never, indeed, was a man of learning and talent who appeared in society so perfectly free from all sorts of pretension or notion of his own importance, or so little solicitous to distinguish himself, or so sincerely willing to give place to every one else. Even upon subjects which he had thoroughly studied he was never in the least impatient to speak, and spoke at all times without any tone of authority; while, so far from wishing to set off what he had to say by any brilliancy or emphasis of expression, it seemed, generally, as if he had studied to disguise the weight and originality of his thoughts under the plainest form of speech and the most quiet and indifferent manner; so that the profoundest remarks and subtlest observations were often dropped, not only with no solicitude that their value should be observed, but without any apparent consciousness that they possessed any. Though the most social of human beings, and the most disposed to encourage and to sympathize with the gaiety and the joviality of others, his own spirits were, in general, rather cheerful than gay, or, at least, never rose to any turbulence or tumult of merriment: and while he would listen with the kindest indulgence to the more extravagant sallies of his younger friends, and prompt them by his heartiest approbation, his own satisfaction might gene. rally be traced in a slow and temperate smile, gradually mantling over his benevolent and intelligent features, and lighting up the countenance of the sage with the expression of the mildest and most genuine philanthropy: It was wonderful, indeed, considering the measure of his own intellect, and the rigid and undeviating propriety of his own conduct, how tolerant he was of the defects and errors of other men. lle was too indulgent, in truth, and favourable to his friends,-and made a kind and liberal allowance for the faults of all mankind, except only faults of baseness or of cruelty, against which he never failed to manifest the most open scorn and detestation. Independent, in short, of his high attainments, Mr. Playfair was one of the most amiable and estimable of men; delightful in his manners, inflexi

ble in his principles, and generous in his affections, he had all that charms in so. ciety or attaches in private: and while his friends enjoyed the free and unstudied conversation of an easy and intelligent associate, they had, at all times, the proud and inward assurance that he was a being upon whose perfect honour and generosity they might rely with the most implicit confidence in life and in death,and of whom it was equally impossible that, under any circumstances, he should ever perform a mean, a selfish, or a questionable action, as that his body should cease to gravitate, or his soul to live.”

At the close of the biographical account, we find a “Journal,” containing a short but very entertaining retrospect of a visit which the Professor paid to London in the year 1782, and of his introduction to several of ihe leading characters, which at that period figured in this metropolis. The first person he mentions is the late Dr. Maskelyne, the astronomer royal, with whom he had formerly spent some time, when engaged in his experiments on the mountain Schehallien in Perthshire; and who gave him so cordial a reception, that he could not allow himself to doubt, that “an acquaintance formed among wilds and mountains is much more likely to be durable than one made up in the bustle of a city.” The astronomer, it seems, had been suspected of sometimes detracting from the discoveries of others, when they interfered with his own; but Mr. Playfair declares he could never perceive any thing of this kind, though he saw him placed in one of those critical situations where envy and jealousy, had they lurked any where within him, could scarcely have failed to make their appearance. The other personages with whom the stranger came chiefly in contact, were Dr. Horsley, Dr. Solander, Mr. Cavendish, Mr. Smeaton, and Drs. Price and Priestley. Of the last mentioned individual, his estimate is so correct and so well expressed, that we take the liberty to quote it at length for the amusement of the reader.

“ Mr. Vaughan and his father are both of them Dissenters, and at their house I often found all the chief men of that interest assembled, Dr. Price, Priestley, Kippis, Tours, and a number of others. To be a Scotsman was far, I soon found, from being any recommendation to these gentlemen, and they seemed to look on the members of every established church with contempt or abhorrence. The manners of Dr. Price were the softest by far of any among them, and I found myself easiest in his company. He is certainly a good mathematician, but politics at present occupy all his thoughts.

“Dr. Priestley has made so great a figure in the world that my anxiety to see him was very great: but his conversation has nothing in it very remarkable. When politics are the subject of discourse he has the same violence with his brethren, and savours not much either of soundness of head or extent of information. On the subjects of chemistry and the doctrine of fixed air, he talked indeed with a great deal of acuteness, and like a man that had been long conversant with experimental philosophy. He is very sanguine in the forming of theories, which he does very often without sufficient data, a fault that is perhaps compensated by the facility with which he afterwards abandons them. On the whole, from Dr. Priestley's conversation and from his writings, one is not much disposed to con. sider him as a person of first-rate abilities. The activity, rather than the force of his genius, is the object of admiration. He is indefatigable in making experiments, and he compensates by the number of them for the unskilfulness with which they often are contrived, and the hastiness with which conclusions are drawn from them. Though little skilled in mathematics, he has written on optics with considerable success; and though but moderately versed in chemistry, he has rendered very considerable service to that science. If we view him as a critic, a metaphysician, and a divine, we must confine ourselves to more scanty praise. In his troversy with Dr. Reid, though he said many things that are true, he has shown

If wholly incapable of understanding the principal point in debate; and

a

when he has affirmed, that the vague and unsatisfactory speculations of Hartley have thrown as much light on the nature of man, as the reasonings of Sir Isaac Newton did on the nature of body, he can scarcely be allowed to understand in what true philosophy consists. "Ås to his theology, it is enough to say that he denies the immateriality of the soul, though he contends for its immortality, and arranges himself on the side of Christianity. These inconsistencies and absurdities will perhaps deprive him of the name of a philosopher, but he will still merit the name of a useful and diligent experimenter.”

When the peace of Europe had been completely re-established by the victory of Waterloo, Mr. Playfair undertook a journey into France, Switzerland, and Italy, with the view of collecting materials for a new edition of his “ Illustrations of the Huttonian Theory," a work which he unfortunately did not live to accomplish. Of the facts which he noted and determined, in the course of his travels, we may perhaps give a short account hereafter; meantime we proceed to lay before our readers an abridged description of the Slide of Alpnach, one of the most surprising mechanical contrivances that reward the ingenuity of the present age.

From the reports of the Chamois hunters employed in the Swiss canton of Unterwalden, it was ascertained that there were immense forests of the finest timber spread out on the mountains, particularly on the south side of Pilatus; but in a situation which the height, the steepness, and the ruggedness of the ground, seemed to render quite inaccessible. Mr. Rupp, a native of Wirtemberg, and a very skilful engineer, then resident in the canton of Schwytz, was induced to visit the locality in question; and he was so much struck with the appearance of the forest, that he conceived the bold project of bring. ing down the trees by no other force than their own weight into the lake of Lucerne, from which the conveyance to the German ocean would be easy and expeditious. The medium height of the forest is about 2500 feet; and the horizontal distance which the trees had to be conveyed, from the spot where they grew to the lake into which they were to be launched, was eight miles and about three furlongs. The declivity is therefore one foot in 17.68: the medium angle of elevation 3° 14' 20".

This declivity, though so moderate on the whole, is, we are told, in many places very rapid: at the beginning the inclination is about one-fourth of a right angle, or 22° 30'; in many places it is 20°; but no where greater than the angle first mentioned, 22° 30'. The inclination continues of this quantity for 500 feet, after which the way is less steep, and often considerably circuitous, according to the direction which the ruggedness of the ground forces it to take.

The Slide in question consists of a sort of trough, built after the form of a cradle, and extending from the forest to the edge of the lake. Three trees squared, and laid side by side, form the bottom of the trough; the tree in the middle having its surface hollowed, so that a rill of water received from distance to distance may be conveyed along the bottom and preserve it moist. Adjoining to the central part of the trough, other trees also squared are laid parallel to the former, in such a manner as to form a trough rounded in the in.terior, and of such dimensions as to allow the largest trees to lie or to move along quite readily. In general it is from five to six feet wide at top, and from three to four in depth, varying, however, in different places according to circumstances. In all it contains about thirty

thirty thousand trees; crosses in its way three great ravines, one at the height of 64 feet, another at the height of 103, and the third, where it goes along the face of a rock, at the height of 157; and in two places it is conveyed under ground.

The trees which descend by this conveyance are spruce firs, very straight, and of great size. All the branches are lopped off; the bark is stripped away, and the surface of course made tolerably smooth. The logs, too, of which the trough is composed, are dressed with the axe, so as to remove all considerable inequalities, and to facilitate the passage of the trees; which, being placed in it with the root end foremost, are launched off in the direction of the lake. As the declivity of the trough at the upper part is very great, the tree in a few seconds acquires such a velocity as enables it to reach the water in the short space of six minutes; a result, as Mr. Playfair observes, altogether astonishing, when it is considered that the distance is more than eight miles, that the average declivity is but one foot in seventeen, and that the route which the trees have to follow is often circuitous, and in some places almost horizontal.

“We saw five trees come down; the place where we stood was near the lower end, and the declivity was inconsiderable, (the bottom of the Slide nearly resting on the surface of the ground,) yet the trees passed with astonishing rapidity. The greatest of them was a spruce fir, a hundred feet, four feet in diameter at the lower end, and one foot at the upper. The greatest trees are those which descend with the greatest rapidity; and the velocity as well as the roaring of this one was evidently greater than of the rest., A tree must be very large to descend at all in this manner: a tree, Mr. Rupp informed us, that was only half the dimensions of the preceding, and therefore only an eighth part of its weight, would not be able to make its way from the top to the bottom. One of the trees that we saw, broke by some accident into two; the lighter part stopped almost immediately, and the remaining part came to rest soon after. This is a valuable fact: it appears from it that the friction is not in proportion to the weight, but becomes relatively less as the weight increases, contrary to the opinion that is generally received

“In viewing the descent of the trees, my nephew and I stood quite close to the edge of the trough, not being more interested about any thing than to experience the impression which the near view of so singular an object must make on a spec. tator. The noise, the rapidity of the motion, the magnitude of the moving body, and the force with which it seemed to shake the trough as it passed, were altogether very formidable, and conveyed an idea of danger much greater than the reality. Our guide refused to partake of our amusement; he retreated behind a tree at some distance, where he had the consolation to be assured by Mr. Rupp, that he was no safer than we were, as a tree when it happened to bolt from the trough, would often cut the standing trees clear over. During the whole time the Šlide has existed, there have been three or four fatal accidents, and one instance was the consequence of excessive temerity."

The trees thus brought down into the lake of Lucerne, are formed into rafts, and floated down the very rapid stream of the Reuss, by which the lake discharges its waters first into the Aar, and afterwards into the Rhine. By this conveyance, which is all of it in streams of great rapidity, the trees sometimes reach Basle in a few days after they have left Lucerne; and there the immediate concern of the Alpnach company terminates. They are afterwards navigated down the Rhine in rafts to Holland, and are afloat in the German ocean in less, than a month from the time they descended from the side of Pilatus, a very inland mountain, not less than a thousand miles distant. We know not the amount of success which, in a pecuniary point of view,