The PraBice Part 11. 



Sights upon the Index, direda Stake to be drove towards Z>^ 

 at a Diftance proportionable to the Length the perpendicular 

 ought to have : You then trace this Line from the Stake 

 to by the firft or fecond Pradice, which Line fliall be per-^ 

 pendicuiar or fquare to the given Line A B\ 



THE SIXTH PRAGTIGE. 



"To defcribe^ with the Cord^ a Perpendicuhr Line at theE?td 

 of a Right Line given^ already- traced. 



Having upon the Paper the Line a 5^ perpendicular to- 

 the Lint I? c J which muft be defcribed upon the Ground : 

 To do this, from the Extremity y4 ©f the traced Line AB^ 

 FIG,- VI. meafure (fuppofe) lo Fathom^ and drive a Stake, as atCf 

 tlien take a double Line of lo or 12 Fathom, and fixing the 

 two End Loops upon the Stakes A and draw the Middle 

 Loop towards Ey and plant aStak^ there and taking the 

 Loop off from the Stake Ay put another Stake through it 

 and draining the End of the Cord^ fo that it range in a Line 

 with the Stakes E and C, as .at the Point fix this Stake: 

 there, and ftrain another Line from the Stake A to the 

 Stake G y the Line G ^l lhall be perpendicular to the Line 

 AB. 



O B S E R V A T I O ISr. 



Tot; may raife this Perpendicular at the End of a Lineal 

 by the help of the Semi-circle, fettitig it plum over the Stake 

 at one of the Extremities^ and direfting the Bafe towards, 

 the other Extremity, you then place the Alhidade or Index, 

 aver po Degrees^ and work as in, the fifth Practice.. 



THE SEVENTH PRAGnCE. 



To draw with the Cord^ a Line parallel to a:Right Line 



traced out. 



'FiQu YiL. Let the two parallel Lines upon the Plan be aB and c d^ ' 

 diftant from one another 12 Fathom, and let the Right Line 

 i^LATE II.. C D be traced upon: the Ground* At each of its Extremities^ 



Cand 



I 



