for Garden ERS5 &c. 53 



the whole Theodolite 5 and the three Points 

 of 90 and 180 Degrees, by moving; the Inftru- 

 inent about its Center, . may give the four Car- 

 dinal Points of Saft,.South, Weft, and North, 

 ad libiturn. VN^j^hin the two Semicircles is a 

 third, having feveral Divifions number'd from 

 the Point of 90, on^both Sides 4, 5, 6, &c. 

 to 12. Their Ufe is for the ready Divifion 

 of a Circle intai4, 3, or 6 Parts, &c. 



Y\&\ 4; Let AD-B be the Semicircle, ACB 

 its Diaajeter, C the Central Point. On C B 

 I would .make an Angle of 60 Deg. 'tis eafy to 

 fee \hu the Diameter of the Inftrument muft 

 be plac'd on C B, and its Center at the Point 

 of thr Angle ^ if you count 60 Degrees from 



B, and prick erti off in your Paper 5 and thro' 



C, aiixHthat fmall Hole, draw C 60 5 60 CB 

 fhall^bean Angle of 60 Degrees, if you would 

 4iavcthe fame Abgle to the left of your In- 

 ftrumeftt, it remaining in the fame Pofture, 

 prick off 60 Degrees from A, and draw C D. 



But where the Theddolite gives the Angle 

 in another Circle A E B, 'tis alfo eafy to fee 

 that A C B reprefents the Diameter of the 

 Inftruhient, and A:E B the Semicircle 5 and, 

 admitting the Index of the Theodolite cut 240 

 Degrees, reckon 'd .from A, that Quantity be- 

 ing, 60 Degrees above a Semicircle \ D B 5 

 prickioff 60 Degrees, reckoned from B or A, 

 (according to the Gircumftance of your Work) 

 and draw GF, or GG. 



If 



