Smoke- proportion of the velocity of the vane to that of the Jack. current of heated air. This is subject to no rule, being changed according to the load of the jack. We imagine that an obliquity of 65 degrees for the outer ends of the vanes will be a good position for the generality of cases. Messinger describes an ingenious contrivance for changing this angle at pleasure, in order to vary the velocity of the motion. Each vane is made to turn round a midrib, which stands out like a radius from the spindle, and the vane is moved by a stiff wire attached to one of the corners adjoining to the axle. These wires are attached to a ring which slides on the spindle like the spreader of an umbrella; and it is stopped on any part of the spindle by a pin thrust through a hole in the spindle and ring. We mention this briefly, it being easily understood by any mechanic, and but of little consequence, because the machine is not susceptible of much precision.

It is easy to see that an increase of the surface of the vanes will increase the power: therefore they should occupy the whole space of the circle, and not consist of four narrow arms like the sails of a windmill. It is better to make many narrow vanes than a few broad ones; as will appear plain to one well acquainted with the mode of impulse of fluids acting obliquely. We recommend eight or twelve at least; and each vane should be so broad, that when the whole is held perpendicular between the eye and the light, no light shall come through the fly, the vanes overlapping each other a very small matter. We also recommend the making them of stiff plate. Their weight contributes to the steady motion, and enables the fly, which has acquired a considerable velocity during a favourable position of things, to retain a momentum sufficient to pull round the spit while the heavy side of the meat is rising from its lowest position. In such a situation a light fly soon loses its momentum, and the jack staggers under its load.

It is plain, from what has been said, that the fly should occupy the whole of that section of the vent where it is placed. The vent must therefore be brought to a round form in that place, that none of the current may pass uselessly by it.

It is an important question where the fly should be placed. If in a wide part of the vent, it will have a great surface, and act by a long lever; but the current in that place is slow, and its impulse weak. This is a fit This is a fit subject of calculation. Suppose that we have it in our choice to place it either as it is drawn in the figure, or farther up at g, where its diameter must be one half of what it is at G. Since the same quantity of heated air passes through both sections, and the section g has only one-fourth of the area of the section G, it is plain that the air must be moving four times faster, and that its impulse is 16 times greater. But the surface on which it is acting is the fourth part of that of the fly G; the actual impulse therefore is only four times greater, supposing both flies to be moving with the same relative velocity in respect of the current; that is, the rim of each moving with the same portion of the velocity of the current. This will be the case when the small fly turns eight times as often in a minute as the large fly for the air is moving four times as quick at g, and the diameter of g is one-half of that of G. Therefore, when the small fly is turning eight times as quick as the great

By this example, more easily understood than a general process, it appears that it is of particular impertance to place the fly in an elevated part of the vent, where the area may be much contracted. In order still farther to increase the power of the machine, it would be very proper to lengthen the spindle still more, and to put another fly on it at a considerable distance above the first, and a third above this, &c.

As the velocity of the current changes by every change of the fire, the motion of this jack must be very unsteady. To render it as adjustable as may be to the particular purpose of the cook, the pulley E has several grooves of different diameters, and the spit turns more or less slowly, by the same motion of the fly, according as it hangs in the chain by a larger or smaller pulley or groove.

Such is the construction of the smoke-jack in its most simple form. Some are more artificial and complicated, having, in place of the pulleys and connecting chain, a spindle coming down from the horizontal axis BC. On the upper end of this spindle is a horizontal contrate wheel, driven by a pinion in place of the pulley C. On the lower end is a pinion, driving a contrate wheel in place of the pulley E. This construction is represented in fig. 6. Others are constructed more simply, in Fig. 6. the manner represented in fig. 7. But our first con- Fig. 7. struction has great advantage in point of simplicity, and allows a more easy adjustment of the spit, which may be brought nearer to the fire or removed farther from it without any trouble; whereas, in the others, with a train of wheels and pinions, this cannot be done without several changes of pins and screws. The only imperfection of the pulley is, that by long use the grooves become slippery, and an ill-balanced joint is apt to hold back the spit, while the chain slides in the grooves. This may be completely prevented by making the grooves flat instead of angular (which greatly diminishes the friction), and furnishing them with short studs or pins which take into every third or fourth link of the chain. If the chain be made of the simplest form, with flat links, and each link be made of an exact length (making them all on a mould), the motion will be as easy as with any wheelwork, and without the least chance of slipping.

It is always of importance to avoid this slipping of the chain by balancing the loaded spit. For this purpose it will be extremely convenient to have what is called a balance-skewer. Let a part of the spit, immediately adjoining to the pulley, be made round, and let an arm be made to turn on it stiffly, so that it may be made fast in any position by a screw. Let a leaden ball be made to slide along this arm, with a screw to fasten it at any distance from the spit. When the meat is spitted, lay it on the racks, and the heaviest side will immediately place itself undermost. Now turn round the balance-skewer, so that it may point straight upwards, and make it fast in that position by the screw. Put the leaden ball on it, and slide it inwards or out

wards

Smoke- wards till it exactly balances the heavy side, which will appear by the spit's remaining in any position in which it is put.

Jack.

Fig.S.

The greatest difficulty is to keep the machine in repair. The essential part of it, the first mover, the fly, and the pinion and wheel, by which its motion is transmitted to the rest of the machine, are situated in a place of difficult access, and where they are exposed to violent heat and to the smoke and soot. The whole weight of the fly, resting on the lower pivot I, must exert a great pressure there, and occasion great friction, even when this pinion is reduced to the smallest size that is compatible with the necessary strength. The pivot must be of hardened steel, tapered like an obtuse cone, and must turn in a conical socket, also of hardened steel or of bell-metal; and this seat of pressure and friction must be continually supplied with oil, which it consumes very quickly. It is not sufficient that it be from time to time smeared with an oiled feather; there must be an iron cup formed round the socket, and kept filled with oil. It is surprising how quickly it disappears; it soon becomes clammy by evaporation, and by the soot which gathers about it. The continued rubbing of the pivot and socket wears them both very fast; and this is increased by hard powders, such as sandy dust, that are hurried up by the rapid current every time that the cook stirs the fire. These, getting between the rubbing parts, cause them to grind and wear each other prodigiously. It is a great improvement to invert these rubbing parts. Let the lower end of the spindle be of a considerable thickness, and have a conical hollow nicely drilled in its extremity. Let a blunt-pointed conical pin rise up in the middle of the oil cup, on which the conical hollow of the spindle may rest. Here will be the same steady support, and the same friction as in the other way; but no grinding dust can now lodge between the pivot and its socket: and if this upright pin be screwed up through the bottom of the cup, it may be screwed farther up in proportion as it wears; and thus the upper pivot g will never desert its hole, a thing which soon happens in the common way. We can say from experience, that a jack constructed in this way will not require the fifth part of the repairs of one done in the other way.

It is of importance that the whole be so put together as to be easily taken down, in order to sweep the vent, or to be repaired, &c. For this purpose, let the cross bar which carries the lower end of the upright spindle be placed a little on one side of the perpendicular line from the upper pivot hole. Let the cock which carries the oil cup and the pivot of the horizontal axis BC be screwed to one side of this cross bar, so that the centre of the cup may be exactly under the upper pivot hole. By this construction we have only to unscrew this cock, and then both axles come out of their places at once, and may be replaced without any trouble. We have sketched in fig. 8. the manner in which this may be done, where M represents a section of the lower cross bar. BCDE is the cock, fixed to the bar by the pins which go through both, with finger nuts a and b on the opposite side. Fi is the hard steel pin with the conical top i, on which the lower end I of the upright spindle AG rests, in the manner recommended as the best and most durable. The pivot of the horizontal axis turns in a hole at E the top of the cock.

# Smollet.

After all, we must acknowledge that the smoke-jack Smokeis inferior to the common jack that is moved by a weight. Jack It is more expensive at first, and requires more frequent repairs; its motion is not so much under command; it occasions soot to be thrown about the fire, to the great annoyance of the cook; and it is a great encumbrance when we would clean the vent.

SMOKE-Farthings. The pentecostals or customary oblations offered by the dispersed inhabitants within a diocese when they made their procession to the mother or cathedral church, came by degrees into a standing annual rent called smoke farthings.

SMOKE Silver. Lands were holden in some places by the payment of the sum of 6d. yearly to the sheriff, called smoke-silver (Par. 4. Edw. VI.). Smoke-silver and smoke-penny are to be paid to the ministers of divers parishes as a modus in lieu of tithe-wood: and in some manors formerly belonging to religious houses,. there is still paid, as appendant to the said manors, the ancient Peter-pence, by the name of Smoke-money (Twisd. Hist. Vindicat. 77.).-The bishop of London anno 1444, issued out his commission, Ad levandum le smoke-farthings, &c.

SMOLENSKO, a large and strong city of Russia, and capital of a government of the same name, with a castle scated on a mountain, and a bishop's see. It is strong by its situation. It has been taken and retakenseveral times by the Poles and Russians; but these last have had possession of it ever since the year 1687. It was taken by the French in their irruption into Russia in 1812. It is seated on the river Nieper, near the frontiers of Lithuania, 188 miles south-west of Moscow. E. Long. 31. 22. N. Lat. 54. 50.

SMOLENSKO, a government of Russia, bounded on the north by Twer, on the east by Moscow, on the south by Kalouga, and on the west by Witepsk. It is full of forests and mountains, but is fertile in grain. The population in 1815 was 965,000.

SMOLLET, DR TOBIAS, an author whose writings will transmit his name with honour to posterity, was born in the year 1720 at a small village within two miles of Cameron, on the banks of the river Leven. He appears to have received a classical education, and was bred to the practice of physic and surgery; and in the early part of his life served as a surgeon's mate in the navy.

The incidents that befel him during his continuance in this capacity served as a foundation for Roderic Random, one of the most entertaining novels in the Englishtongue. He was present at the siege of Carthagena; and in the before-mentioned novel he has given a faithful, though not very pleasing, account of the management of that ill-conducted expedition, which he censures in the warmest terms, and from circumstances which fell under his own particular observation.

His connection with the sea seems not to have been of long continuance; and it is probable that he wrote several pieces before he became known to the public by his capital productions. The first piece we know of with certainty ia a Satire in two parts, printed first in the years 1746 and 1747, and reprinted in a Collection of his Plays and Poems in 1777. About this period, or some time before, he wrote for Mr Rich an opera intitled Alceste, which has never been performed nor printed. At the age of 18 he wrote a tragedy intitled The

Regicide,

degree of success was insured to every thing known or Smollet. suspected to proceed from his hand. In the course of a few years, the Adventures of Peregrine Pickle appeared; a work of great ingenuity and contrivance in the composition, and in which an uncommon degree of erudition is displayed, particularly in the description of the entertainment given by the Republican Doctor, after the manner of the ancients. Under this personage the late Dr Akenside, author of The Pleasures of Imagination, is supposed to be typified; and it would be difficult to determine whether profound learning or genuine humour predominate most in this episode. other episode of the Adventures of a Lady of Quality, likewise inserted in this work, contributed greatly to its success, and is indeed admirably executed; the materials, it is said, the lady herself (the celebrated Lady Vane) furnished.

Smollet. Regicide, founded on the story of the assassination of James I. of Scotland. In the preface to this piece, published by subscription in the year 1749, he bitterly exclaimed against false patrons, and the duplicity of theatrical managers. The warmth and impetuosity of his temper burried him, on this occasion, into unjust reflections against the late George Lord Lyttleton and Mr Garrick the character of the former he characterised in the novel of Peregrine Pickle, and he added a burlesque of the Monody written by that nobleman on the death of his lady. Against Mr Garrick he made illiberal ill-founded criticisms; and in his novel of Roderick Random gave a very unfair representation of his treatment of him respecting this tragedy. Of this conduct he afterwards repented, and acknowledged his errors; though in the subsequent editions of the novel the passages which were the hasty effusions of disappointment were not omitted.

However, in giving a sketch of the liberal arts in his History of England, he afterwards remarked, "the exhibitions of the stage were improved to the most exquisite entertainment by the talents and management of Garrick, who greatly surpassed all his predecessors of this and perhaps every other nation, in his genius for acting, in the sweetness and variety of his tones, the ir resistible magic of his eye, the fire and vivacity of his action, the eloquence of attitude, and the whole pathos of expression.

Not satisfied with this public declaration, he wrote an apology to Mr Garrick in still stronger terms. With these ample concessions, Mr Garrick was completely satisfied; so that in 1757, when Dr Smollet's comedy of the Reprisals, an afterpiece of two acts, was performed at Drury Lane theatre, the latter acknowledged himself highly obliged for the friendly care of Mr Garrick exerted in preparing it for the stage; and still more for his acting the part of Lusignan in Zara for his benefit, on the sixth instead of the ninth night, to which he was only intitled by the custom of the theatre.

The Adventures of Roderic Random, published in 1748, 2 vols 12mo, a book which still continues to have a most extensive sale, first established the Doctor's reputation. All the first volume and the beginning of the second appear to consist of real incident and character, though certainly a good deal heightened and disguised. The Judge his grandfather, Crab and Potion the two apothecaries, and 'Squire Gawky, were characters well known in that part of the kingdom where the scene was Jaid. Captains Oakhum and Whiffle, Doctors Mackshane and Morgan, were also said to be real personages; but their names we have either never learned or have now forgotten. A bookbinder and barber long eagerly contended for being shadowed under the name of Strap. The Doctor seems to have enjoyed a peculiar felicity in describing sea characters, particularly the officers and sailors of the navy. His Trunnion, Hatchway, and Pipes, are highly finished originals; but what exceeds them all, and perhaps equals any character that has yet been painted by the happiest genius of ancient or modern times, is his Lieutenant Bowling. This is indeed nature itself; original, unique and sui generis.

By the publication of this work the Doctor had acquired so great a reputation, that henceforth a certain

3

An

These were not the only original compositions of this stamp with which the Doctor has favoured the public. Ferdinand Count Fathom, and Sir Launcelot Greaves, are still in the list of what may be called reading novels, and have gone through several editions; but there is no injustice in placing them in a rank far below the former. No doubt invention, character, composition, and contrivance, are to be found in both; but then situations are described which are hardly possible, and characters are painted which, if not altogether unexampled, are at least incompatible with modern manners; and which ought not to be, as the scenes are laid in modern times.

The last work which we believe the Doctor published was of much the same species, but cast into a different form-The Expedition of Humphrey Clinker. It consists of a series of letters, written by different persons to their respective correspondents. He has here carefully avoided the faults which may be justly charged to his two former productions. Here are no extravagant characters nor unnatural situations. On the contrary, an admirable knowledge of life and manners is displayed; and most useful lessons are given applicable to interesting but to very common situations.

We know not whether the remark has been made, but there is certainly a very obvious similitude between the characters of the three heroes of the Doctor's chief productions. Roderic Random, Peregrine Pickle, and Matthew Bramble, are all brothers of the same family. The same satirical, cynical disposition, the same generosity and benevolence, are the distinguishing and characteristical features of all three: but they are far from being servile copies or imitations of each other. They differ as much as the Ajax, Diomed, and Achilles of Homer. This was undoubtedly a great effort of genius; and the Doctor seems to have described his own character at the different stages and situations of his life.

Before he took a house at Chelsea, he attempted to settle as practitioner of physic at Bath; and with that view wrote a treatise on the waters; but was unsuccessful, chiefly because he could not render himself agreeable to the women, whose favour is certainly of great consequence to all candidates for eminence, whether in medicine or divinity. This, however, was a little extraordinary; for those who remembered Dr Smollet at that time, cannot but acknowledge that he was as grace. ful and handsome a man as any of the age he lived in ;

besides,