DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.1456#0147
112. Tfie PraBice Part II.
The First Observation.
If the oblong Square were much bigger than this, yoa
muft then raife, with the Inftrument, two Perpendiculars
upon the Extremities of the Line A B, according to the
Obfervation onthefixth Trattice, and make each of thole
Perpendiculars equal to the Breadth of the Parallelogram.
The Second Observation.
T o draw a perfect Square, the Practice is the fame with
that above, laving that the two Perpendiculars muft be drawn
as long as the Bafe of the Square.
THE THIRTEENTH PRACTICE.
To deferibe} with the Liney an Irregular Figure of four Sides.
Suppose the Irregular Figure to be a b c d, from the
Point a, with the Interval ac, defcribe with the Compafles
an Arch, as c e ; and from the Points, with the Interval bd,
make another Arch, as df; meafure the Lengths a b, which
iuppofe 25 Fathom, ac 9 Fathom, bd 11 Fathom, and the
Cords of the Arches or Diftances from c to e 10 Fathom, and
11G. XIII. from /to d 14 Fathom. Then trace upon the Ground the Line
or Bale AB of 25 Fathom long, and carry from A to E
9 Fathom, and from B to F 11 Fathom j plant two Stakes
in the Points E and F, and taking a Cord of nine Fathom
fix'd to the Stake A, and one of 10 Fathom long fix'd to the
Stake E, bring their Ends to meet in the Point C, and drive
a Stake there : Do the like on the other Side, as upon the
Stake B fix a Cord of 11 Fathom, and one of 14 upon the
Stake F, bringing their Extremities together in the Point 7),
and tracing the Lines AC, CD, T) B, you form, with the
Bale AB, the four-fided Figure propofed.
THE FOURTEENTH PRACTICE.
To draw an irregular Figure off our Sides with the Inftrument,
The four-fided Figure abed, is here Jfiippofed to be
confiderably bigger than the foregoing j as the Bale ab to
be
The First Observation.
If the oblong Square were much bigger than this, yoa
muft then raife, with the Inftrument, two Perpendiculars
upon the Extremities of the Line A B, according to the
Obfervation onthefixth Trattice, and make each of thole
Perpendiculars equal to the Breadth of the Parallelogram.
The Second Observation.
T o draw a perfect Square, the Practice is the fame with
that above, laving that the two Perpendiculars muft be drawn
as long as the Bafe of the Square.
THE THIRTEENTH PRACTICE.
To deferibe} with the Liney an Irregular Figure of four Sides.
Suppose the Irregular Figure to be a b c d, from the
Point a, with the Interval ac, defcribe with the Compafles
an Arch, as c e ; and from the Points, with the Interval bd,
make another Arch, as df; meafure the Lengths a b, which
iuppofe 25 Fathom, ac 9 Fathom, bd 11 Fathom, and the
Cords of the Arches or Diftances from c to e 10 Fathom, and
11G. XIII. from /to d 14 Fathom. Then trace upon the Ground the Line
or Bale AB of 25 Fathom long, and carry from A to E
9 Fathom, and from B to F 11 Fathom j plant two Stakes
in the Points E and F, and taking a Cord of nine Fathom
fix'd to the Stake A, and one of 10 Fathom long fix'd to the
Stake E, bring their Ends to meet in the Point C, and drive
a Stake there : Do the like on the other Side, as upon the
Stake B fix a Cord of 11 Fathom, and one of 14 upon the
Stake F, bringing their Extremities together in the Point 7),
and tracing the Lines AC, CD, T) B, you form, with the
Bale AB, the four-fided Figure propofed.
THE FOURTEENTH PRACTICE.
To draw an irregular Figure off our Sides with the Inftrument,
The four-fided Figure abed, is here Jfiippofed to be
confiderably bigger than the foregoing j as the Bale ab to
be