DOI Page / Citation link:
https://doi.org/10.11588/diglit.62828#0319
fquare 45,6, lying on the level ground. Draw from g, a per-
pendicular to g on the new horizon Z>/. From 4 draw a line to
the uppermoft g, and the line will pafs through the diagonal of
the fquare reprefented on the inclined plane ; which is a clear
demonflration of the truth of the whole.
The truth of the method may be proved, alfo, by drawing
a line from A to D, the diftance laid on from the new hori-
zon h l\ for the line cuts the vifual at 1, as in the other
method.
Prob. IX. Fig. ii. Plate XVII.
To find the Reprefentation of a Square, fituated in a Plane oblique
both to the Ground and to the Picture.
This figure may, to the workman, appear intricate and
perplexed; but he ought not to be difcouraged at the light
of an affemblage of lines, till, after having made a reafon-
able attempt to underftand them, he finds it not ealily at-
tained. But it is to be noticed, that there are feveral more
lines than what are abfolutely neceffary for reprefenting the
fquare fimply confidered; becaufe I have fhown different me-
thods to effect the fame thing; and becaufe the whole procefs
is fhown from firft to laft, that the reader might have a clear
H h underftanding
pendicular to g on the new horizon Z>/. From 4 draw a line to
the uppermoft g, and the line will pafs through the diagonal of
the fquare reprefented on the inclined plane ; which is a clear
demonflration of the truth of the whole.
The truth of the method may be proved, alfo, by drawing
a line from A to D, the diftance laid on from the new hori-
zon h l\ for the line cuts the vifual at 1, as in the other
method.
Prob. IX. Fig. ii. Plate XVII.
To find the Reprefentation of a Square, fituated in a Plane oblique
both to the Ground and to the Picture.
This figure may, to the workman, appear intricate and
perplexed; but he ought not to be difcouraged at the light
of an affemblage of lines, till, after having made a reafon-
able attempt to underftand them, he finds it not ealily at-
tained. But it is to be noticed, that there are feveral more
lines than what are abfolutely neceffary for reprefenting the
fquare fimply confidered; becaufe I have fhown different me-
thods to effect the fame thing; and becaufe the whole procefs
is fhown from firft to laft, that the reader might have a clear
H h underftanding