Fig. 8. shews a balance according to a construction used by Arnold, and specified by him to the commissioners of longitude. The expansion weights are cylindrical, and are adjusted upon the arm by screwing and there is an inner rim upon which three weights are adjusted by sliding. These serve to regulate the going of the time-piece in different positions.

If an uniform ring, with two or more radii placed at equal regular distances, and in all other respects alike, were to be poised on its axis, as a balance, no part would preponderate; but it would remain at rest in any position; and if we suppose the axis itself to be a spring, such as a piece of stretched wire, and we overlook the difference of tension in the wire, which might arise from the weight of the balance itself, in different positions, it is obvious that all the vibrations of that balance, through equal arcs, would be performed in equal times, whether the balance were made to vibrate parallel to the horizon, or in any other position. But in the balance of a time-piece, the pivots of its axis bear very differently, according to the position of the chronometer; and it requires some management to make the frictions the same, whether the axis be turning on one of its ends, or upon the two cylindrical faces of the pivots. And still more than this, since the balance itself has a permanent figure, compared with the spring, which in every part of the vibration alters its distance from the axis, and in every part of its length has a different degree of rotatory motion, it cannot be expected, nor does it happen, that a balance, which is found to be in poize, along with its spring, when out of the chronometer, will make equal vibration, as to time, in all positions when in its place. And in addition to these difficulties, there is one part of the arc of vibration, where the force of the spring, and the inertia of the balance, are not simply in opposition to each other, but are combined with the maintaining power: namely, during the action of escape. The remedy for all these difficulties, which is happily adopted in chronometers for use at sea, is to place the axis in a vertical position; by which means the balance itself is not affected by gravity; but for pocket time-pieces, the ingenuity of the artist is called upon for expedients, of which it would be not easy to exhibit a complete theory. The general principle commonly used, and also adopted by Arnold and Earnshaw, as far as can be gaVOL. VI.

thered from the little they say in their specifications to the commissioners of longitude, is to consider the balance, when out of adjustment for position, as a pendulum weight above and below the centre of suspension, acted upon by gra vity, and at the same time urged to a quiescent point by the force of elasticity. In these circumstances the vibrations will be quickest when the point of stable equilibrium is downwards, and they will be slowest in the opposite position of the machine. This leads to the remedy of diminishing either the weight of the radius, or that side which is lowest when the rate is most quick. Thus, if one of the two adjusting screws, in fig. 7, were downwards, in the position of quickest rate, that screw would require to be screwed a very little quantity inwards, and the opposite screw to be screwed a like quantity outwards, in order to remedy this imperfection without much change in the other adjustments And if a like imperfection were found in the vibrations of the balance, when tried in a vertical position, having the lowest point at rest, in a line at right angles to the line passing through the radii, a similar alteration must be made in the expansion weights, either by a careful flexure of the circular arcs, or by altering the quantities of those weights; or else by means of small screws tapped into the weights themselves, and directed towards the centre, like the weights at the extremities of the radii.

By these, and other correspondent means, the balance may be made to keep time, in all those positions wherein its plane shall be perpendicular to that of the horizon; but even in these trials, very great pains and labour may be required to produce a high degree of accuracy; and in this course of operation, the skil ful workman may be under the necessity of preparing a great number of expansion weights and regulating screws, to be applied in trial, whenever the course of adjustment in one part shall carry him beyond the general conditions of the whole machine. And after all, as the quantity of action, in the spring, must alter the quantity of pendulous effect, in this curious and delicate time-measurer, it may be doubted, whether the adjustments for position in the vertical balance can be effectual any longer than while the arcs of vibration continue permanent. This consideration leads us to the necessity of an adjustment in the maintaining power, in order that the vibrations shall not fall off;

montoire,

at the same time that it affords one of the strongest arguments in favour of a re notwithstanding the experiment of Arnold, which showed that a sea-chronometer (face up) kept the same rate, when those arcs were greatly varied.

When the balance has been adjusted for position in the vertical situation, it does not follow, as a matter of course, that it will keep the same time with its plane horizontal, or face up and face down. In the former cases, the effect of gravity still appears to be combined with that of elasticity, though under circumstances of adjustment; in the latter, gravity seems to be out of the question. If the rate should demand adjustment with the axis vertical, in order to make it agree with that which obtains when the balance is vertical, it appears necessary, that either the inertia or the elastic force should be altered. The former seems to demand such changes of the screws or weights, as may alter the effective radius of the balance; the latter requires a change of the spring itself. The artists, with whom the writer of this article has conferred, did not seem to have clear notions of any direct method for effecting the purpose here pointed out. It appeared, that they have recourse to several expedients; but that, in general, the rate, face up, of a timepiece, which has been well adjusted in other respects, does not require much additional adjustment.

From all these considerations, with others, into which brevity forbids us to enter, together with those which relate to the choice and preparation of materials, and the delicacy and truth of workmanship, the reader will be able to form some judgment of the intelligence and skill, with which, chiefly under the sanction of the British government, this important manufacture has been pursued, and like. wise of the ample field for improvement, which remains for the exertions of future artists. See PENDULUM, CLOCK, TRAIN, and WATCH-WORK.

HOROPTER, in optics, a right line drawn through the point where the two optic axes meet, parallel to that which joins the centres of the two eyes, or the two pupils.

HOROSCOPE, in astrology, is the degree of the ascendant, or the star that rises above the horizon at a certain moment, which is observed in order to predict some future event, as the success of a design, the fortune of a person who was at that instant born, &c. The same name

is also given to a scheme or figure containing the twelve houses, in which are marked the situation of the heavens and stars, in order to form predictions. See HOUSE.

HOROSCOPE lunar, the point from whence the moon proceeds when the sun is in the ascending point of the east.

HORS, de son fee, an exception, to avoid an action brought for rent issuing out of certain lands, by him that pretends to be the lord, or from some customs and services; for if the defendant can prove the land to be within the compass of his fee, the action fails.

HORSE. See Equus.

HORSE dealers. Every person, exercising the trade or business of an horse-dealer, must take out a licence from the Stamp Office, for which he shall pay annually, if within London, Westminster, the bills of mortality, the parish of St. Pancras, or the borough of Southwark, twenty pounds; elsewhere, ten pounds.

Horse-dealers, who shall, after January 1, 1796, carry on the said business without having obtained a licence under the act of 36 George III. c. 17, shall be liable to be assessed the duties on riding-horsees, and shall deliver lists thereof as other persons.

HORSES. It shall be lawful for any person, native or foreigner, at any time, to ship, lade, and transport, by way of merchandize, horses into any parts beyond the seas, in amity with his majesty, paying for each horse, mare, or gelding, 58. and no

more.

No person convicted for feloniously stealing a horse, gelding, or mare, shall have the privilege of clergy. 1 Ed. VI. c. 12. And not only all accessaries before such felony done, but also all accessaries after such felony, shall be deprived and put from all benefit of their clergy, as the principal, by statute heretofore made, is or ought to be.

If an horse be stolen out of the stable, or other curtilage of a dwelling-house, in the night time, it falls under the denomination of burglary; if in the day-time, it falls under the denomination of larceny from the house; and in either case there is a reward of 401. for convicting an offender, and the prosecutor is entitled to a certificate, which will exempt him from all parish and ward offices, in the parish and ward where the burglary, or larceny, is committed, and which may be once assigned over, and will give the same exemption to the assignee as to the original proprietor.

Great abuses having arisen, and many horses having been stolen, from the facili ty and safety of disposing of them to those who keep slaughter-houses for horses, some regulations and restrictions seemed absolutely necessary. It was no uncommon thing for horses of great value to be sold for the purpose of making food for dogs, the thief rather choosing to receive twenty shillings for a stolen horse, without fear or danger of detec. tion, than venture to dispose of him publicly,though he might possibly have found a purchaser who would have given as many pounds for him. These considerations induced the legislature to pass the act of 26 Geo. III. c. 71, for regulating these slaughter-houses.

Killing or maiming horses. Where any person shall, in the night-time, maliciously, unlawfully, and wilfully, kill or destroy any horses, sheep, or other cattle, of any person, every such offence shall be adjudged felony, and the offender shall suffer as in the case of felony. 22 and 23 Car. II. c. 7.

Offenders may be transported for seven years, either at the assizes, or at the sessions, by three justices of the peace; one to be of the quorum.

By the 9 Geo. I. c. 22. commonly called the black act, it is enacted, that if any person shall unlawfully and maliciously kill, maim, or wound, any cattle, every person so offending, being thereof lawfully convicted in any county of England, shall be adjudged guilty of felony, and shall suffer death, as in cases of felony, without benefit of clergy. But not to work corruption of blood, loss of dower, nor forfeiture of lands or goods.

Prosecution upon this statute shall, or may, be commenced within three years from the time of the offence committed, but not after.

If a horse, or other goods, be delivered to an innkeeper, or his servants, he is bound to keep them safely, and restore them when his guest leaves the house.

If a horse be delivered to an agisting farmer, for the purpose of depasturing in his meadows, he is answerable for the loss of the horse, if it be occasioned by the ordinary neglect of himself or his servants. If a man ride to an inn, where his horse has eat, the host may detain the horse till he be satisfied for the eating, and without making any demand. But a horse committed to an inn-keeper can only be detained for his own meat, and not for that of his guest, or any other horse; for the chattels, in such case, are

only in the custody of the law for the debt which arises from the thing itself, and not for any other debt due from the same party. By the custom of London and Exeter, if a man commit a horse to an inn-keeper, if he eat out his price, the innkeeper may take him as his own, upon the reasonable appraisement of four of his neighbours; which was it seems a custom, arising from the abundance of traffic with strangers, that could not be known so as to be charged with an action. But it hath been holden, though an inn-keeper in London may, after long keeping, have the horse appraised and sell him, yet, when he has in such case had him appraised, he cannot justify the taking him to himself at the price he was appraised at. And this cannot be done at any other place by the common law, unless there is some special custom.

HORSE, in naval affairs, a rope reaching from the middle of a yard to its extremities, and depending about two or three feet under the yard, for the sailors to tread on while they are loosings, reefing, or furling the sails, rigging out the studding sail-booms, &c. The same word is used for a thick rope extending in a perpendicular direction near the fore or aftside of a mast, for the purpose of hoisting some yard or extending a sail upon it: when before the mast, it is used for the square sail, whose yard is attached to the horse by means of a traveller which slides up and down When it is abaft the mast, it is intended for the try-sail of a snow, but it is seldom used in this position, except in sloops of war that occasionally assume the appearance of snows to deceive the enemy.

HORSE leech. See HIRUDO.

HORTUS siccus, a dry garden, an appellation given to a collection of specimens of plants, carefully dried and preserved. The value of such a collection is very evident, since a thousand minutiæ may be preserved in the well-dried specimens of plants, which the most accurate engraver would have omitted. We shall, therefore, give some methods of drying and preserving an hortus siccus. Specimens ought to be collected when dry, and carried home in a tin box. Plants may be dried by pressing in a box of sand, or with a hot smoothing iron. Each of these has its advantages. If pressure be employed, a botanical press may be procured. The press is inade of two smooth boards of hard wood, eighteen inches long, twelve broad, and two thick. Screws must be fixed in each corner with

nuts. If a press cannot easily be had, books may be employed. Next some quires of unsized blotting paper must be provided. The specimens, when taken out of the tin box, must be carefully spread on a piece of pasteboard, covered with a single sheet of the paper quite dry; then place three or four sheets of the same paper above the plant, to imbibe the moisture as it is pressed out; it is then to be put into the press. As many plants as the press will hold may be piled up in this manner. At first they ought to be pressed gently. After being pressed for twenty-four hours or so, the plants ought to be examined, that any leaves or petals which have been folded may be spread out, and dry sheets of paper laid over them. They may now be replaced in the press, and a greater degree of pressure applied. The press ought to stand near a fire, or in the sunshine. After remaining two days in this situation, they should be again examined, and dry sheets of paper be laid over them. The pressure then ought to be considerably increased. After remaining three days longer in the press, the plants may be taken out, and such as are sufficiently dry may be put in a dry sheet of writing paper. Those plants which are succulent may require more pressure, and the blossom paper again renewed. Plants which dry very quickly, ought to be pressed with considerable force when first put into the press; and if delicate, the blossom paper should be changed every day. When the stem is woody, it may be thinned with a knife, and if the flower be thick or globular, as the thistle, one side of it may be cut away, as all that is necessary, in a specimen, is to preserve the character of the class, order, genus, and species. Plants may be dried in a box of sand in a more expeditious manner, and this method preserves the colour of some plants better. The specimens, after be ing pressed for ten or twelve hours, must be laid within a sheet of blossom paper. The box must contain an inch deep of fine dry sand, on which the sheet is to be placed, and then covered with sand an inch thick; another sheet may then be deposited in the same manner, and so on, till the box be full. The box must be placed near a fire for two or three days. Then the sand must be carefully removed, and the plants examined. If not sufficiently dried, they may again be replaced in the same manner for a day or two. In drying plants with a hot smoothing iron, they must be placed within several

sheets of blotting paper, and ironed till they become sufficiently dry. This method answers best for drying succulent and mucilaginous plants. When properly dried, the specimens should be placed in sheets of writing-paper, and may be slightly fastened by making the top and bottom of the stalk pass through a slip of the paper, cut nearly for the purpose.Then the name of the genus and species should be written down, the place where it was found, nature of the soil, and the season of the year. These specimens may be collected into genera, orders, and classes, and titled and preserved in a portfolio or cabinet. The method of preserv ing many of the cryptogamous plants is more difficult, on account of the greater quantity of moisture which they contain, and the greater delicacy of their

texture.

HOSPITALS, are institutions founded for the relief of the sick and miserable.

HOSPITAL, Pennsylvania. This is one of the best organized institutions in the United States. The following account of it, together with hints for amending its police, is extracted from a work, entitled "A Treatise, containing a plan for the internal organization and government of Marine Hospitals, in the United States," &c. by Dr. Wm. P. C. Barton, professor of botany in the university of Pennsylvania :

An account of the Pennsylvania Hospital, and its internal police

It is obvious, that in proposing regulations and arrangements for the internal administration of hospitals, whether naval, military, or civil, or in suggesting plans for the structure of wards, and other domestic contrivances, but little can be offered that is new. In both cases, the best we can do is, to take a view of some of the similar institutions in highest repute, and cull from their various and well-devised plans, such as are most useful, and consistent with the principles of economy and neatness.

With this view, I deem it far from irrelevant to the object of this work, to present some account of an institution, with the internal police of which I have long been familiarized; and which I believe, from a comparative view with the first hospitals of England, to be one of the best conducted institutions of the kind, perhaps, in any country. The hospitals of London are, it is true, conducted on a much more extensive plan: St. Thomas's,

Guy's, and St. Bartholomew's, being perhaps twice as large as the one of which I am speaking-the Pennsylvania Hospital. But I think I can with truth assert, that the regularity, neatness, and regard to comfort, which characterize this noble institution, eminently entitles it to a preference to any of these, at least so far as it goes. The architectural plan of the building, its beautiful and healthy situation, surrounded as it is by a constant current of fresh air, unimpeded by any buildings, or other hindrances, render this institution one of the most salubrious resorts for the sick or afflicted, that could possibly be contrived in the midst of a large and populous city.

The hospital presents a south front; the wings which intersect the long buildings, that join them to the main edifice, at right angles, present the one an east, and the other a west, front. The centre building, or main edifice, is sixty-four feet in front, elevated above all the adjoining buildings, (being three stories high) and projecting beyond them both front and back. On the summit of the roof is a sky-light, forming the apex of the operating theatre, which receives its light entirely from this. Two large staircases, leading to the several wards and apartments up stairs, are constructed in this building, running from the main hall.

Adjoining this centre edifice, on the east, is a building 80 feet front, and 27 feet deep, two stories high, from the surface of the ground, and three, including the range of windows in the area below. This building is divided, in its upper stories, into two wards, extending nearly to its entire length and breadth; and the lower or basement story is subdivided into a row of cells on the south side, and a lobby on the north. The two long wards are ventilated by openings into the chimnies, of which there are four in each ward, near the ceiling. At the east end of these wards, two small apartments are partitioned off, about 10 feet square, the one intended for a pantry, and the other for a lodging-room for the assistant nurses of the ward. At the other, or west termination of the upper ward, two small rooms, of the same size, are partitioned off, for patients who may require a separate room. The lower ward extends in length to the centre building.

Intersecting this long building, at right angles, and adjoining it, facing the east, is a wing two stories high, running north and south, extending in length 110 feet. In the middle of this wing, opposite to

and communicating with the long ward, is an hall, 28 feet square, including the stair-case, projecting beyond the line of the wing sufficiently to cover the cornice, and raised one story above it, with a cupola. In the north and south ends of this wing are two sick wards, and between them and the hall, on each side of it, are two lodging-rooms for the nurses. The arrangement in the second story is the

same.

Adjoining the centre edifice, on the west, is a long building, 34 feet deep, divided into 42 cells, for lunatics, with a window in each. These cells front north and south, and are separated in the middle by a long lobby, about 12 feet wide, which is lighted from the cells, by the small windows over each door. The west wing, which intersects this long building at right angles, is in all respects subdivided like the east. The structure upstairs is the same as that of the first story, being divided into wards, and a double row of cells.

In the basement story, there is likewise a double row of cells, all round the wing and long building, the windows of which open into the area. All the cells are warmed by flues in their partition walls, communicating with the chimney, and opening into wall stoves, the doors of which are in the lobbies-one stove warms two rooms. The whole extent of the buildings, from east to west, is 278 feet. In consequence of the length of the wings crossing the long wards, and rows of cells, the east and west fronts present a finished and agreeable appearance.

Detached from the main building, and at a convenient distance from it, near the east wall, is a two story building: divided into a kitchen, pantry, lodging-room for a nurse, and four small wards for venereal patients.

Near the west wall are two buildings, two stories high, the one containing washing, ironing, and drying rooms; the other stables, &c.

The different apartments in this hospital are as follow:

Centre building. Kitchen, scullery, steward's dining room, maid's lodging-room, in the basement story.

A library-room, on the first floor, an

apothecary's shop, ditto, manager's room, ditto, steward's room, ditto, The contributors' room, in the second story, chambers for the resident physician, pupils, and steward, ditto.

3