enotes a kind of string, of twisted wire; serving to hang watches, tweezers cases, and other valuable toys upon. The invention of this piece of curious work is owing to the English; whence, in foreign countries, it is denominated the English chain. These chains are usually either of silver or gold, some of gilt copper; the thread or wire of each kind to be very fine.—For the fabric, or making of these chains; a part of the wire is folded into little links of an oval form; the longest diameter about three lines; the shortest one. These, after they have been exactly soldered, are again folded into two; and then bound together or interwoven, by means of several other little threads of the same thickness; some whereof, which pass from one end to the other, imitate the warp of a stuff; and the others, which pass transverse, the woof. There are at least four thousand little links in a chain of four pendants; which are by this means bound so equally, and withal so firmly together, that the eye is deceived, and takes the whole to consist of one entire piece.

Chain is also a kind of measure in France, in the trade of wood for fuel. There are chains for wood by tale, for wood by the rope, for faggots, for cleft wood, and for round sticks. There are also chains for measuring the theaves of all sorts of corn, particularly with regard to the payment of tithes; for measuring pottles of hay, and for measuring horses. All these are divided into feet, inches, hands, &c., according to the use they are designed for. Chain, in surveying, is a measure, consisting of a certain number of links of iron wire, usually a hundred; serving to take the dimensions of fields, &c. This is what Mersenius takes to be the arvipedium of the ancients.

The chain is of various dimensions, as the length or number of links varies: that commonly used in measuring land, called Gunter's chain, is in length four poles or perches; or sixty-six feet, or a hundred links; each link being seven inches $\frac{2}{3}$. Whence it is easy to reduce any number of those links to feet, or any number of feet to links.

This chain is entirely adapted to English measures; and its chief convenience is in finding readily the numbers contained in a given field. Where the proportions of square feet and acres differ, the chain, to have the same advantages as Gunter's chain, must also be varied. Thus, in Scotland, the chain ought to be of 74 feet, or 24 Scotch ells, if no regard be had to the difference between the Scotch and English foot; but if regard be had to this difference, the Scotch chain ought to consist of 74$\frac{1}{2}$ English feet, or 74 feet four inches and $\frac{1}{3}$ of an inch. This chain being divided into an hundred links, each of these will be 8$\frac{1}{3}$ inches.

That ordinarily used for large distances, is in length 100 feet; each link one foot. For small parcels, as gardens, &c., is sometimes used a small chain of one pole, or 16 feet and a half length; each link one inch $\frac{2}{3}$.

Some in lieu of chains use ropes; but these are liable to several irregularities, both from the different degrees of moisture, and of the force which stretches them. Schwenterus, in his Practical Geometry, tells us, he has observed a rope fifteen feet long reduced to fifteen in an hour's time, by the mere falling of a hoar frost. To obviate these inconveniences, Wolfius directs, that the little strands whereof the rope consists be twisted contrariwise, and the rope dipped in boiling hot oil, and when dry, drawn through melted wax. A rope thus prepared will not get or lose anything in length, even though kept under water all day.

**Chain Pump.** See **Pump.**

**Chain Shot,** two bullets with a chain between them. They are used at sea to shoot down yards or masts, and to cut the shrouds or rigging of a ship.

**Top Chain,** on board a ship, a chain to sling the sail yards in time of battle, in order to prevent them from falling down when the ropes by which they are hung happen to be shot away or rendered incapable of service.

**Chain Wales,** or **Channels,** of a ship, (porteboissoirs), are broad and thick planks projecting horizontally from the ship's outside, abreast of and somewhat behind the masts. They are formed to extend the shrouds from each other, and from the axis or middle line of the ship, so as to give a greater security and support to the masts, as well as to prevent the shrouds from damaging the gunwale, or being hurt by rubbing against it. Every mast has its chain wales, which are either built above or below the second deck ports in a ship of the line; they are strongly connected to the side by knees, bolts, and standards, besides being confined thereto by the chains, whose upper ends pass through notches on the outer edge of the chain wales, so as to unite with the shrouds above.

**Chains,** in Ship-Building, are strong links or plates of iron, the lower ends of which are bolted through the ship's side to the timbers.

**Hanging in Chains,** a kind of punishment inflicted on murderers. By stat. 25 Geo. II. c. 37, the judge shall direct such to be executed on the next day but one, unless Sunday intervene; and their bodies to be delivered to the surgeons to be dissected and anatomized; and he may direct them afterwards to be hung in chains. During the interval between sentence and execution, the prisoner shall be kept alone, and sustained only with bread and water. The judge, however, hath power to reprieve the execution, and relax the other restraints of the act.

**Chain Island,** an island lately discovered by Captain Wallis in the South sea. It seemed to be about five miles long and as much broad, lying in the direction of north-west and south-east. It appeared to be a double range of woody islands joined together by reefs, so as to compose one island of an oval figure, with a lake in the middle. The trees are large, and from the smoke that issued from the woods, it appeared to be inhabited. W. Long. 145° 54'. S. Lat. 17° 23'.

**Chajotli,** or **Chayori,** a Mexican fruit of a round shape, and similar in the husk with which it is covered to the chestnut, but four or five times larger, and of a much deeper green colour. Its kernel is of a greenish white, and has a large stone in the middle, which is white, and like it in substance. It is boiled, and the stone eaten with it. This fruit is produced by a twining perennial plant, the root of which is also good to eat.

**Chair,** (Cathedra), was anciently used for the pulpit, or suggestum, whence the priest spoke to the people.

It is still applied to the place where professors and regents in universities deliver their lectures, and teach the sciences to their pupils; thus, we say, the professor's chair, the doctor's chair, &c.

**Curule Chair,** was an ivory seat placed on a car, wherein were seated the prime magistrates of Rome, and those to whom the honour of a triumph had been granted.

**Sedan Chair,** a vehicle supported by poles, wherein persons are carried; borne by two men. There are 200 chairs allowed by act of parliament; and no person is obliged to pay for a hackney chair more than the rate allowed by the act for a hackney coach driven two-thirds parts of the said distance. 9 Ann. c. 23. § 8. Their number is since increased by 10 Ann. c. 19. and 12 Geo. I. c. 12. to 400. See **Hackney Coaches.**