DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.62828#0072
( 24 )
with more exaCtnefs than can be drawn on a floor by a fquare.
But, as I intend giving fome directions to the Upholfterer
how to lay down a room in an accurate manner, fo that a carpet
may be properly cut by his plan, I fhall at prefent fay nothing
more on this fubjeCt.
Problem IV. Fig. 4.
To draw a perpendicular line by a fcale of equal parts, as
by a common rule, or by a rod divided.
Operation.-—Let the line G V be the line required to raife a
perpendicular from. Let V be the propofed point, and from
any fcale of equal parts lay down ten of thofe parts from the
point V towards G. Take then fix of thofe parts (or fix inches
of the common rule) and turn the arch 1.2 at pleafure. Again,
take ten parts, or ten inches of your rule, and place the end of
the rule or rod on the eighth of thofe ten parts or inches, and
with the other hand, by a pencil, interfeCt the arch 1.2, by
which a point will be gained exadly perpendicular to V, as
required.
This problem will be of ufe to the Cabinet-maker and
Upholfterer when neither fquare or compafies are at hand*
For inftance, if a Cabinet-maker would cut a board acrofs
perfectly fquare, without compares, chalk line, or fquare, if he
have but a rod, let him proceed thus:
8 Divide-
with more exaCtnefs than can be drawn on a floor by a fquare.
But, as I intend giving fome directions to the Upholfterer
how to lay down a room in an accurate manner, fo that a carpet
may be properly cut by his plan, I fhall at prefent fay nothing
more on this fubjeCt.
Problem IV. Fig. 4.
To draw a perpendicular line by a fcale of equal parts, as
by a common rule, or by a rod divided.
Operation.-—Let the line G V be the line required to raife a
perpendicular from. Let V be the propofed point, and from
any fcale of equal parts lay down ten of thofe parts from the
point V towards G. Take then fix of thofe parts (or fix inches
of the common rule) and turn the arch 1.2 at pleafure. Again,
take ten parts, or ten inches of your rule, and place the end of
the rule or rod on the eighth of thofe ten parts or inches, and
with the other hand, by a pencil, interfeCt the arch 1.2, by
which a point will be gained exadly perpendicular to V, as
required.
This problem will be of ufe to the Cabinet-maker and
Upholfterer when neither fquare or compafies are at hand*
For inftance, if a Cabinet-maker would cut a board acrofs
perfectly fquare, without compares, chalk line, or fquare, if he
have but a rod, let him proceed thus:
8 Divide-