DOI Page / Citation link:
https://doi.org/10.11588/diglit.62828#0068
Then with the foot of your compafles, fixed on 7, turn the
arch* 1.8, and, without any alteration of the inftrument, place
its foot in i, and turn the arch 7.9 at pleafure.
Second, Take the fpace 1.8, and place it on the arch 7.9
drawn indefinitely t. Then from 1 to 9, draw a right fine,
which will be parallel, to the line 7.8.
Thus far it fliould be obferved, that the problem teaches
to draw two lines parallel, both with difpatch and accuracy.
Laftly, with your compafles, opened at random, lay on
the divifions 1, 2, 3,4, 5, 6, on both lines, firfl: from 1 to 9, then
from 7 to 8, and by drawing lines from each correfpondent
jfbint, the given line 1.7 will then be divided as required.
A little reflection will point out the reafon of this, if we
confider that the lines 7.8,1.9, are perfectly parallel to each
other.
For if the divifions laid on each line be greater or lefs than
thofe fought for, yet lines drawn acrofs to each refpective divi-
fion will cut the line to be divided in the fame points ; becaufe
* Arch, from arcus, a bow, Lat. and, when ufed in Geometry, implies “ any part of a
circumference of a circle.”
•f That is, without bounds or limits.
what
arch* 1.8, and, without any alteration of the inftrument, place
its foot in i, and turn the arch 7.9 at pleafure.
Second, Take the fpace 1.8, and place it on the arch 7.9
drawn indefinitely t. Then from 1 to 9, draw a right fine,
which will be parallel, to the line 7.8.
Thus far it fliould be obferved, that the problem teaches
to draw two lines parallel, both with difpatch and accuracy.
Laftly, with your compafles, opened at random, lay on
the divifions 1, 2, 3,4, 5, 6, on both lines, firfl: from 1 to 9, then
from 7 to 8, and by drawing lines from each correfpondent
jfbint, the given line 1.7 will then be divided as required.
A little reflection will point out the reafon of this, if we
confider that the lines 7.8,1.9, are perfectly parallel to each
other.
For if the divifions laid on each line be greater or lefs than
thofe fought for, yet lines drawn acrofs to each refpective divi-
fion will cut the line to be divided in the fame points ; becaufe
* Arch, from arcus, a bow, Lat. and, when ufed in Geometry, implies “ any part of a
circumference of a circle.”
•f That is, without bounds or limits.
what