14. New Principles of Gardening: 
as. alfo cm, chk, bl, bh, ez, and ef, then will the Circum- 
ference be divided into twelve equal Parts, each containing 
thirty “Degrees: Divide a f, am, €c. each into three equal Parts, 
and then will the Czrcle be divided into thirty fix, each con- 
taining ten Degrees. Laftly, divide each of thofe Divifions 
into ten equal Parts, by the preceding ProsLEMs of Sect. I. 
and the Circumference will be divided into three hundred and 
Sixty equal Parts, as required. 0, E.F. 
PROBLEM ly. 
O find the Center of a Circular Arch, and the whole 
Diameter of the Circle, of which the given Arch is a Part 
or Segment. 
Fig.xxIX _ Practice. Let aéc be the Circular Arch given ; affume 
three Points therein, as 2, b,c, and by Pros. XIll. Sect. 1, find 
the Center, Sc. 9, E. F. ra | 
ass S28 EM Vs" 
; A Circle being given, to find its.Center, 
a a 
? : tote 
Fig. xxx, . Practice. Let abc be the Circle given; affume therein 
three Points, as 2, 6, c, and by Pros. XIIL Sect. I. find the 
Center, Sc. Q, EF. 
we On. Sis. yp. ROB LEM ep aro oe 
G Fin ge an Ellipfis (aelbk h,) ¢o any Length given, 
| acdb. 5 : | 
Fig-XXXL  DeFiniTion. AnELipsts (Greek) is 2 Geometrical Figure, » 
comprehended in one only Line, but that not circular, nor ha- 
. Ving all its Parts equally refpecting the Center, but two Focus 
Pomts, as esd. tL 
n Evtiesis is generated by an oblique Section of a Cone, 
and is to be defcribed divers Ways, as following : 
Prac- 
