The PraBice Part II. 



Stake F, and making it juft touch or graze upon that of 

 range it by the Stakes FandD, till it cut the Circumference 

 of one of the two Circles, in a Point where you drive a 

 Stake, as at G ; do the fame on the other Side, for planting, 

 the Stake H upon the Circumference ; and from the Center 

 F, without Ihiftingthe Line, draw the Arch G H, till you 

 co'me to the Stakes G and H. This done, fliift the Line, 

 and putting it upon the Stake E, do the fame thing for 

 planting the Stakes L and /, and trace the Arch IL i then , 

 joining thefe Tracks with the two Portions of Circles at the 

 Extremities A and you deface the reft of thefe Circles . 

 marked with Points, that you find within the Oval,_ which , 

 is all that will remain vifible, and will in every refped be. 

 like that of a in the Plan. 



THE NINETEENTH PRACTICE... 



To trace an O-val^ the two Diameters of which are determined' 



upon the Paper. 



Let the Ovsl he abed, the longeft Diameter of which 

 is 20 Fathom, and the fliorteft 12, as quoted upon the Pa- 

 per, Trace upon the Ground the Line AB 20 Fathom long, 

 which terminate by two Stakes, and divide it into twocquaL 

 Parts, as in the Point upon which raife a Perpendicular 

 of 12 Fathom long, by the fourth Praftice ; take the Half 

 of this, which is lix Fathom, and meafuring a Cord of that 

 Length, lay it upon the great Diameter A B, from one of its 

 Extremities, as from the Point B towards F, divide the 

 Space that remains' between F', and the Center E, into three 

 c equal Parts, and fet off one of thefe Parts upon the fame 

 ' Line beyond the Point F; as G: Tlien take the Diftance 

 fwm the Point G to the Center E, and f^t it off upon the 

 other oppofite Side, as from E to H, planting two Stakes- 

 there, to range with thofe of the two Ends A and B ; and 

 from thefe Stakes G and H, draw the two equilateral Tri- 

 angles HJG, andfJLG, according to the firft Obfervation 

 of the eleventh Praftice: This done, prolong the Sides of 

 the Triangles indefinitely, and trace them lightly, as IHN^ . 



and:. 



