which insert in the third column; and thus proceed from angle to angle; sending your assistant with a flag-staff before you, till you return to the place where you began. This is the manner of taking field-notes by what are called fore-sights. But the generality of mearsmen frequently set themselves in disadvantageous places, so as often to occasion two or more stations to be made, where one may do, which creates much trouble and loss of time; we will therefore shew how this may be remedied by taking off back-sights: thus, let your assistant stand, with his staff, at the point where you begin your survey, as at A; leaving him there, proceed to your next angle B, where you fix your instrument so that you may have the longest view possible towards C. Having set the instrument in a horizontal position, turn the south part of the box next your eye, and having cut your object at A, reckon the degrees to the south point of the needle, which will be the same as if they were taken from the object to the instrument, the direction of the index being the same. Let the degree be inserted in the field-book, and the stationary distance be measured and annexed thereto, in its proper column; and thus proceed from station to station, leaving your object at the last point you left, till you return to the first station A.

A back and fore-sight may be taken at one station, thus with the south of the box to your eye, observe from B the object A, and set down the degree in your field-book, cut by the south end of the needle. Again, from B observe an object at C, with the north of the box to your eye, and set down the degree cut by the south point of the needle; thus you have the bearings of the lines AB and BC; you may then set up your

instrument at D, from whence take a back-sight to C, and a fore-sight to E; thus the bearings may be taken quite round, and the stationary distances being annexed to them, will complete the field-book.

If your needle be pointed at each end, in taking foresights you may turn the north part of the box to your eye, and count your degrees to the south part of the needle, as before; or you may turn the south of the box to your eye, and count your degrees to the north end of your needle. But in back-sights, you may turn the north of the box to your eye, and count your degrees to the north point of your needle; or you may turn the south of the box to your eye, and count your degrees to the south end of the needle. The brass ring in the box is divided on the side into 360 degrees; thus, from the north to the east into 90, from the north to the west into 90, from the south to the east into 90, and from the south to the west into 90 degrees; so the degrees are numbered from the north to the east or west, and from the south to the east or west.

The manner of using this part of the instrument is this—having directed your sights to the object, whether fore or back, as before, observe the two cardinal points of your compass the needle lies between (the north, south, east, and west being called the cardinal points,) putting down those points together by their initial letters, and thereto annexing the number of degrees, counting from the north or south, as before; thus, if the point of your needle lies between the north and east, north and west, south and east, south and west points in the bottom of the box, then put down NE, NW; SE, SW, annexing thereto the number of degrees

cut by the needle on the side of the ring, counting from the north or south, as before. But should the needle point exactly to the north, south, east, or west, you are then to write down N, S, E, or W, without annexing any degree.

To Protract a Field-book, when the Angles are taken from the Meridian.

On your paper draw lines parallel to each other, at an inch asunder, or at any other convenient distance; on the left end of the parallels put N for north, on the right S for south; put E at the top for east, and W at the bottom of your paper for west.

Let the following field-book be that which is to be protracted, the bearings being taken from the meridian by the circumferentor, and the stationary distances measured by the two-pole chain

Pitch upon any convenient spot on your paper for your first station, as at 1, on which lay the centre-hole your protractor, with a protracting pin; then if the

of

degrees be less than 180°, turn the arc of your protractor downwards, or towards the west; but if more than 180°, upwards, or towards the east.

Or, if the right hand be made the north, and the left the south, the west will then be up, and the east down. In this case, if the degrees be less than 180, turn the are of your protractor upwards, or towards the west; and if more, downwards, or to the east.

By the foregoing field-book, the first bearing is 283, turn the arc of your protractor upwards, keeping the pin in the centre hole; move the protractor so that the parallel lines may cut opposite divisions, either on the ends of the scale, or on the degrees, and then it is parallel. This must be always done before you lay off your degrees, then by the edge of the semicircle, keeping the protractor steadywith the pin, prick the first bearing 283; and from the centre point, through that point or prick, draw a black line with the pen, on which, from a scale of equal parts, or from the scale's edge of the protractor, lay off the distance 55C. 20L. At the end of the first station, or at 2, which is the beginning of the second, with the pin place the centre of the protractor, turning the arc up, because the bearing of the second station is more than 180 degrees, viz. 3483, place your protractor parallel, as before, and by the edge of the semicircle, with the pin prick at that degree, through which and the end of the foregoing station, draw a black line, and on it set the distance of that station. In the same manner proceed through the whole, observing to turn the arc of your protractor down, when the degrees are less than 180.

In all protractions, if the end of the last station falls exactly in the point you begin at, the field work and

protraction are truly taken and performed; if not, an

error must have been committed in one of them. In such a case, make a second protraction: if this agrees with the former, and neither meet or close, the fault is in the field work, and not in the protraction; and then a re-survey must be made.

The direction here given to survey by the circumferentor and chain, together with the field book and method of plotting, have been taken almost verbatum from the old edition of Gibson's Surveying. Having plotted the work, the area may be found by the method shewn in the parish survey.

Some surveyors who use the circumferentor, prefer the method of surveying by what is termed latitude and departure-but as the author does not wish to encourage the use of so defective an instrument by dwelling too long on its practice, he begs to refer such as may be anxious to see this particular method, to the work