Thesaurarium mathematicae, or, The treasury of mathematicks containing variety of usefull practices in arithmetick, geometry, trigonometry, astronomy, geography, navigation and surveying ... to which is annexed a table of 10000 logarithms, log-sines, and log-tangents / by John Taylor.

PROP. VII. How by the Semicircle, to take the Plot of a Field at t〈…〉〈…〉 Stations, which lieth remote from you, when either by opposition of Enemies you may not, or by some other Impediment you cannot come into the same.

Admit the Figure A, B, C, D, E, F, to be a Field into which by no means you can possibly enter, and yet of necessity the Plot thereof must be had, for the obtaining of which chuse any two Stations, it mattereth not whether near at hand or far off, so that all the Angles may be seen. Let your two Stations be H and L, (the full length of the Field if possible) then place your Instrument at H, and fixing it as is* 1.1 afore shewed, direct your sights to the several Angles of the Field, viz. A, B, C, &c. orderly one after another, observing their degrees as is afore taught, noting it down in your Field-book: then take up your Instrument, leaving a mark in its room at H, And measure with your Chain from Hunto L, your second Station, which note down in your Field-book; Then placing your In∣strument at L, your second Station, and as is be∣fore taught, fixing it there, make the like Obser∣vation to the several Angles, viz. A, B, C, D, &c. as at the first Station H, and note it down in your Field-book also, And having so done you have finished, and your Work standeth thus.

Observations at the first Sta∣tion H, are

The Angle from H the first Station, unto L the se∣cond Station, is 180° 00', the* 1.2 Stationary distance HL, is 60 Chains.

Observations at the second Sta∣tion L, are

1 Angles	D	M
A	104	00
B	88	07
C	59	00
D	48	00
E	26	00
F	21	30
2Angles	D	M
A	16	00
B	39	00
C	50	09
D	74	00
E	100	00
F	29	15

Notes

• * 1.1

  Fig. 56.
• * 1.2

  Fig. 56.