The compleat surveyor containing the whole art of surveying of land by the plain table, theodolite, circumferentor, and peractor ... : together with the taking of all manner of heights and distances, either by William Leybourn.

CHAP. VIII. How to protract or lay down a Distance taken, ac∣cording to the directions of the two last Chapters, upon paper, by help of your Protractor or line of Chords.

WHen you make any observations in the field, by the Theodolite or Circumferentor, you are to note down the quantities of the severall lines and an∣gles observed in the field, in a Book or paper, so that they may be ready at hand when you come to protraction, and this is the usuall way.

Suppose it were required to draw upon paper or pastboard the true symetry or proportion of the distance taken in the last Chapter.

First, upon your paper draw a line at length as RQ, then, upon one end thereof, as at R, place the center of your Protractor, and ••ay the Meridian line EF of the Protractor, directly upon the line

[illustration]

QR: then, (because the angle QRS is 45 degrees 10 minutes, therefore, against 45 degrees 10 minutes of your Protractor, make a mark upon your paper with your Protracting pin (as is before taught Chap. 2.) and draw the line RS. This done, from any Scale, take

your stationarie distance RQ 176 foot, and set it from R to Q. Then upon the point Q (because the angle RQS contains 110 degreet 30 minutes) place the center of the Protractor, and turn it about till the line RQ lie directly under 110 degrees, then (at the point E of the Protractor) make a mark with your protracting pin, and through that point draw the line QS, which will cut the line RS in the point S: then if you measure the length of the lines QS and RS, by the same Scale from whence you took 176 for the line QR, you shall finde the line QS to contain 303, and the line RS to contain 400, exactly agreeing with the numbers found in the last Chapter.

[illustration]