[ 7<*o ] 
To reduce a Scale to ft exactly your general Map. 
Firft fee what Extent the whole Survey takes on 
the Charts you laid it down by in the Field, viz. the 
greateft Depth and Breadth, as from the Specimen of 
the general Map it may appear. 
Depth 
The Whole 
Breadth 
N 9 2.= 
= 10 Inches. 
N 9 8. =5 Inches. 
N° 6. 
16 H 
N 9 9. i 6 ik 
N 9 11. 
1 6 if 
10. 16 H 
N° 13. 
10 f 
11. 1 
7 • 61 - 
53 ? 
' 
The Whole 
60 f | qr. 
Then having fixed on the Size of the general Map 
to be 16,37 Square, I form a Scale of 60 -per Inch, 
that may juft extend the whole Breadth of the 16,37 
Inches? by which you may form all the Squares, and 
Parts of Squares, in Depth and Length, as above? and 
at Fig. 3- is divided. 
The Breadth of the whole Map, by a Scale of 3 2, 
is 60,62 Inches, which I would reduce into the Com- 
pafs of 16* and -5-= 16,37 Inches. 
Divide 60,62 by 16,37, gives 3.7, which multiplied 
by 3,20, makes the Product 11,84, that is 11 Chains 
84 Links in an Inch, the Scale for the general Map. 
Thus have I done all I intended ?but fliall obferve, 
that feveral of thefe Tables have been made, and, as 
People have fanfied, with Alterations and Additions ; 
but all Variations are not really Improvements. The 
fetting it horizontally by Spirit — Tubes, may be 
curious enough: But as the Difference is very incon- 
fiderable and indifccrnible, when it Hands Two 
or 
