The quantity of each person's share being now determined, the common may be divided by one or other of the methods already given.

CASE II. To divide a common of variable value among any number of claimants, in proportion to the values of their respec

tive estates.

In this case, the map of the common with the quantity of every different quality of land thereon, must be prepared, as well as the quantities and qualities of the several parts of each claimant's estate, in order that the values of both the common and each person's estate may be properly ascertained; the quality lines on the common being marked out by the valuer or valuers, previous to the survey being made.

When the survey of the common is completed and mapped, with the quality lines laid down thereon, the several qualities. must be number 1, 2, 3, &c., with the values of the land corresponding to each number, as determined by the valuers, who are usually called "Commissioners." Most surveyors use the letters of the alphabet to denote the different values of the land: thus a may represent five shillings, b six shillings, &c., per acre per annum. By using the letters in this manner a multiplicity of figures, which may be confounded with other numbers, is avoided.

ROADS, QUARRIES, WATERING PLACES, &c., REQUIRED TO BE SET OUT PREVIOUS TO ENCLOSING COMMONS, WASTES, &c.

Before the lands of a common or waste can be divided and allotted, both public and occupation roads must be set out in the most convenient manner; they should be straight and, as far as practicable, at right angles to one another, as this arrangement not only facilitates the division of the land, but contributes greatly to the economy of cultivation with the plough. All old roads that may be deemed unnecessary may be stopped up and

allotted to the different claimants, or diverted into more convenient directions, at the discretion of the Commissioners.

Portions of the common are now to be set apart for quarries, sand or gravel pits, if such abound in the common. The ground, thus set out, is considered as the common property of the several claimants, for the purpose of building, making roads, &c. Also, if there are any good springs or ponds on the common, they must be left unenclosed, in like manner, for common use; or the water must be conveyed from them by drains or channels to more convenient situations, previous to the enclosure of the common.

The lord of the manor in some places claims th of the common, in someth. &c. His claim, whatever it be, must be next set out, after its value has been determined from the whole value of the common. The lord of the manor will also be further entitled to his share of common, in proportion to his property, in the same manner as the other proprietors.

Lastly, when the roads, watering places, quarries, sand and gravel pits, and manorial rights have been set out, the remainder of the common must be divided equitably, as it respects quantity, quality, and situation, among the proprietors of lands, tenements, houses, cottages, &c., situated in the parish or township where the inclosure is to be made.

THE METHOD OF DIVIDING AND ALLOTTING THE REMAINING PART OF THE COMMON.

Having found the sum of the values of each proprietor's estate, and the whole value of the remaining part of the common to be divided, proceed to find the value of each proprietor's share by the following

RULE. As the sum of the value of each proprietor's estate, is to the whole value of the common remaining to be divided, so is the value of each proprietor's estate to his share of the value of the common.

It will be quite unnecessary to give an example in this case, as the laying out of the shares of the several claimants, after their respective values have been found by the above Rule, would only be a repetition of the methods already given, on a large scale; and after the work of laying out the several inclosures on the ground has been completed, the last enclosure or share of the common must be of the same value as that assigned by the rule, or so very near to it that the error is of no importance; otherwise a mistake has been made which must be immediately rectified.

For further information respecting the law for the inclosure of commons, waste lands, &c., the student may consult the following

ACTS OF PARLIAMENTS.

GENERAL ACT.

"An Act for consolidating in one Act, certain provisions usually inserted in Acts of Inclosure; and for facilitating the mode of proving the several facts, usually required on the passing of such Acts." (Act. 41 Geo. III., chap. 109. 1801.)

Since the General Act, the following Acts have been passed, relating to inclosures.

1. An Act to amend the Law respecting the inclosing of open fields, pastures, moors, commons, and waste lands in England." (Act 1 & 2 Geo. IV. chap. 23; April 19th, 1821.)

2. An Act for facilitating the inclosure of open and arable fields in England and Wales." (Act 6 & 7 Will. IV. chap. 115; August 20th, 1836.)

3. "An Act to extend the Powers and Provisions of the several Acts relating to the enclosure of open and arable fields in England and Wales." (Act 3 & 4 Vict. chap. 31; July 23rd, 1840.)

4. An Act to facilitate the enclosure and improvement of commons and lands held in common, the exchange of lands, and the division of intermixed lands; to provide remedies for defective or incomplete Executions, and for the non-execution of the Powers of general and local Inclosure Acts; and to provide for the revival of such Powers in certain cases." (Act 8 & 9 Vict. chap. 118; August 8th, 1845.)

5. "An Act to amend the Act to facilitate the inclosure and improvement of commons." (Act 9 & 10 Vict. chap. 70; August 26th, 1846.)

NOTE. All the above Acts may be procured through any bookseller in town or country.

END OF PART L

PART II.

LEVELLING.

CHAPTER I.

DEFINITION OF LEVELLING.

Br the art of levelling the inequalities of the upper boundary of any section of the earth's surface may be shewn, and thence may be determined the several heights of any number of points in that boundary, above or below an assumed line, called a level line; though, in reality, this line is a great circle of the earth, and is such as would be derived from a section of the surface of still water.

LEVELLING INSTRUMENTS.

(1.) Levelling instruments all depend on the action of gravity of these the plumb-line, on which the mason's level depends, is the most simple; but it cannot be used in extensive operations, on account of its practical inconvenience. The fluid, or water level, in all its modifications, is also found inconvenient for extensive practice.

(2.) Spirit levels are now commonly used, as the most accurate instruments for finding the differences of level, or vertical distances between two stations: of these there are three, which we shall proceed to describe, namely, the Y level, Troughton's, and Gravatt's levels.

The foregoing figure represents this instrument. A is an achromatic telescope, resting on two supporters, which in shape resemble the letter Y; hence the name of the instrument. The lower ends of these supporters are let perpendicularly into a strong brass bar, which carries a compass box C. This compass is convenient for taking bearings, and has a contrivance for throwing the needle off its centre, when not in use. One of the Y supporters is fitted into a socket, and can be raised or lowered by the screw B.

Beneath the compass box, which is generally of one piece with the bar, is a conical axis passing through the upper of two parallel plates, and terminating in a ball supported by a socket. Immediately above the upper parallel plate is a collar, which can be made to embrace the conical axis tightly by turning the clamping screw E; and a slow horizontal motion can be given to the instrument by means of the tangent screw D. The two parallel plates are connected together by the ball and socket already mentioned, and are set firm by four mill-headed screws, which turn in sockets fixed to the lower plate, while their heads press against the under side of the upper plate, and thus serve the purpose of setting the instrument truly level.

Beneath the lower parallel plate is a female screw, adapted to the staff head, which is connected with brass joints to three mahogany legs, of exactly the same construction as those already described for supporting the theodolite.

The spirit level 77 is fixed to the telescope by a joint at one end, and a capstan-headed screw at the other, to raise or depress it for adjustment.

(3.) Previous to using this instrument the following adjustments must be attended to.

1. The Adjustments of the telescope for parallax and collima

tion.

2. The adjustment of the bubble tube.

3. The adjustment of the axis of the telescope perpendicularly to the vertical axis.

1. The adjustment for parallax and collimation have already been described, (p. 76,) being the same as those required for the theodolite.

2. The adjustment of the bubble tube.-Move the telescope till it lies in the direction of two of the parallel plate screws, and by giving motion to these screws bring the air-bubble to the centre of its run. Now reverse the telescope carefully in the Ys, that is, change the places of its ends; and should the bubble not settle in the same point of the tube as before, it