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Then take from your Scale the Length of the Line pq 135, and fet it from p to q, and through the point q draw the Line KC, making it to contain in Length 216: Nexa take from your Scale 112, and fet it from q to R, and through the point R draw the Line KD, and take from your Scale 217, and fet it from K to D; and fo proceed till you have finished your Plot. And, Laftly, Through the feveral points ABCD, &c. draw the Boundary Lines.
How to take the Plot of a Field by the plain Table, at one or more Stations
There are three ways for doing this Work. The first performs the Work by meafuring every Line from the Inftrament to the Angles, and is a good way, when it can be done. The fecond does it, by Meafuring only the Stations or Distances, and is very quick, but not fo fure and exact as the other; yet if it be manag'd by a fkilfull Artift, it will come near enough the matter in many Cafes; as Measuring for Mowing or Reaping Fields by the Acre, or in Cafe of Law Suits, when you cannot come nigh the Ground to be Meafured.
The 3d is by way of Circulation, the In ftrument being oft to be planted, and the plot to be measured by going round about it, by which thick Woods or Bogs may be measured.
In all thefe Methods two things are to be performed.
1. At every Angle where there is no Mark already, as a Tree, or Bush, &c. one must be placed with a white Paper; one must go from Angle to Angle.
2. When ever you have occafion to plant your Inftrument more then once, you muft be fure to let it ftand just as it did the firft time, that is, for Situation, which if your Needle be good, will perform the Work, but is not thought fufficient without a backfight and fore-fight. Now for the firft Method.
To take the Plot of a Field at one Station, in any part thereof, from whence you may fee all its Angles or Corners.
Fig. 92. Suppofe ABCDEF be a Field to be measured. Firft, Cause marks to be fet up in every Corner of it; then make Choice of fome convenient place therein, from whence you may beft view all the Angles thereof; in which place at H, plant your Table (covered with a Sheet of elean Paper,) turn the Table about till the Needle ftand over the Flower de Luce, and fo faften it with the Screw-pin, that the Table ftir not. Then placing your Index upon the Table, lay the Fiducial Edge thereof upon the point H, reprefenting the
place of your Station; and draw a Line with your Compaffes point, by the fide of the Index upon the Paper; which done, direct your fight to B, (Aill keeping the Edge of your Index to the point H) and draw a Line as before; and fo in like manner direct your Index to C, D, E and F, drawing the Lines upon the Paper by the Edge of your Index, with the point of your Compaffes, and fo having finished the fame, measure withyour Chain the diftance of every of thofe Marks, from the place of y our Station at H, and then by the help of your Scale and Compaffes, fet the fame diftances from the point H, in the Lines drawn upon the Table, making a fmall prick with your Compaffes point at the end of every one of them, then with the point of your Black-lead Pencil, draw a finall Line from one point to another, as namely from A to B, from B to C, from C to D, &c. fo fhall you have upon your Table the exact Plot of your Field.
To take the Plot of any Field at one Station, in any one Angle thereof, from whence all o ther Angles may be feen.
Fig.93 Firft,as before,fet upMarks in every Corner of the Field, as at BCDEFG; then make Choice of the most convenient Angle therein; from whence you may beft view all the reft, as A; and having fixt and having fixt your Table
there, as before is taught, apply the Index to the point A, and direct the fights to B ; then draw a Line AB upon the Paper, and with your Chain measure the Length there. of, and fet it down by the help of your Scale from A to B.
Then from the faid point A, turn your fights to C, your fecond Mark, and then draw with one point of your Compafles upon the Paper the Line AC, measuring the diftance, and fetting down the Lergh as you were before taught.
In like manner direct your fights to D, E, Fand G, and drawing Lines upon your Paper, measure with your Chain the Diftance of each of the fame Angles, from your Station point at A, where your Tab'e is planted; then with your Compaffes take from the Scale the refpective diftances, and and fet them down from the point upon the feveral Lines, and fo defcribe the Lines AB, BC, CD, DE, EF, FG, GA; which will exactly reprefent the juft Figure of your Field.
How to take the Plot of a Field at two Stations, when all the Angles cannot be feen at one.
It oftentimes happeneth, through Hills or the largenefs of Grounds, that you cannot from any one place of the Field fee all the Corners thereof; in which Cafe you must
make Choice of two convenient places within the fame: So that here you are to perform at two Stations, what you did be. iore at one.
Fig. 91. Suppofe therefore, that the Figure CDEFGHIKLM, be a Field to be plotted; I make Choice of two Stations, within the fame, as A and B, where I can view all the Angles. And firft, I plant my Table at A, from whence I can fee the Angles M CDEF; then placing the Edge of my In. dex upon the point A, I direct my fights feverally to the Angles within my View, as to MCDEF, drawing Lines, as is directed in the Figure, which done, I measure every one of them with my Chain, and note them down from iny Scale, as formerly.
Then (my Table remaining fixt) I view the other parts of the Field, and make choice of the point B for my fecond Station, becaufe from thence, I can fee all the other Ai gles of the Field; then fetting up a Mark there, I go back to my firft Station at A (where my Table ftands fixed, as I left it,) upon which point I move my Index, till through the fights thereof, I efpy the Mark at B, which done, I draw a Lineby the Edge of the Index, with the point of my Compafs,extending it the Length of my Table, as is reprefented by the Line ZX, which being thus performed, I meafure my Stationary diftance