DOI Page / Citation link:
https://doi.org/10.11588/diglit.19575#0177
i6o PER
vou would make a plan of a cube B C, draw two occult or dotted
lines from the extremes B C to the point of fight; then, to give
the breadth, take the fame meafure B C, and fet it off on the ter-
reftrial line C F ; and from F draw a line to the point of diftance
D, and where this line interfects the firft ray C, in the point G,
will be the diminution of the plan of the cube B H G C.
If you would have an object farther towards the middle, take
the breadth and the diftance of the bafe line, as I K; and, to
have the depth, fet it as you would have it on the fame bafe as
L M, and its width both on L M : Then, from L and M, draw
occult lines to the point of diftance D ; and, from the points
N O, where thofe lines interfect the ray K, draw parallels to the
terreftial line, and you will have the fquare Q_P O N.
After the fame manner you may fet off the other fide of the
fquare which fhould be on the bafe, as B H G C is here trans-
ferred to V. The points M and T, which are only two feet
from the point S, afford a very narrow figure in X, as being very
near.
2. Of the bafe line and a fingle point of dijlance. Since the
depths and widths may be had by the means of this bafe line,
there is no need of any further trouble in making of fquares, as
Ihall be fhewn in this example :
Suppofe a row of trees or columns is to be made on each fide ;
on the bafe line lay down the place and the diftance between
them, with their breadth or diameters, as A B C D E F G, fig. 2;
then, laying a ruler from the point of diftance O, to each of the
points ABCDEFG, the interfections it makes on the vifual
ray A H will be the bounds of the objects defired.
To fet them off on the other fide, upon the ray G H, fet one
foot of the compafies upon the point of the eye H, and with the
other ftrike an arch ; the point wherein this cuts the ray G H,
will be the correfponding bound.
Thus M will be the fame with N, and fo of the reft; through
which drawing parallels, you will have the breadths.
And, as for the length, you may make it at pleafure, fetting it
off from A, as for inftance, to P, and then from P, drawing a
line to H; and, where this cuts the other parallels, will be form-
ed the plan required, which you may make either round or fquare.
3. Not to deceive one's felf in the meajures. Never put any ob-
jects that are intended to be within the plan on the fide of the
point of diftance, where you are to draw lines for the manage-
ment of the depth.
Thus, fuppofe A B, fig. 3, the vifual ray, whereon the mea-
fures are to be marked ; if you would produce the points C and
D through the fame, do not draw the lines from the point of dif-
tance E, but from that oppofite thereto, F ; or, if C and D were
on
vou would make a plan of a cube B C, draw two occult or dotted
lines from the extremes B C to the point of fight; then, to give
the breadth, take the fame meafure B C, and fet it off on the ter-
reftrial line C F ; and from F draw a line to the point of diftance
D, and where this line interfects the firft ray C, in the point G,
will be the diminution of the plan of the cube B H G C.
If you would have an object farther towards the middle, take
the breadth and the diftance of the bafe line, as I K; and, to
have the depth, fet it as you would have it on the fame bafe as
L M, and its width both on L M : Then, from L and M, draw
occult lines to the point of diftance D ; and, from the points
N O, where thofe lines interfect the ray K, draw parallels to the
terreftial line, and you will have the fquare Q_P O N.
After the fame manner you may fet off the other fide of the
fquare which fhould be on the bafe, as B H G C is here trans-
ferred to V. The points M and T, which are only two feet
from the point S, afford a very narrow figure in X, as being very
near.
2. Of the bafe line and a fingle point of dijlance. Since the
depths and widths may be had by the means of this bafe line,
there is no need of any further trouble in making of fquares, as
Ihall be fhewn in this example :
Suppofe a row of trees or columns is to be made on each fide ;
on the bafe line lay down the place and the diftance between
them, with their breadth or diameters, as A B C D E F G, fig. 2;
then, laying a ruler from the point of diftance O, to each of the
points ABCDEFG, the interfections it makes on the vifual
ray A H will be the bounds of the objects defired.
To fet them off on the other fide, upon the ray G H, fet one
foot of the compafies upon the point of the eye H, and with the
other ftrike an arch ; the point wherein this cuts the ray G H,
will be the correfponding bound.
Thus M will be the fame with N, and fo of the reft; through
which drawing parallels, you will have the breadths.
And, as for the length, you may make it at pleafure, fetting it
off from A, as for inftance, to P, and then from P, drawing a
line to H; and, where this cuts the other parallels, will be form-
ed the plan required, which you may make either round or fquare.
3. Not to deceive one's felf in the meajures. Never put any ob-
jects that are intended to be within the plan on the fide of the
point of diftance, where you are to draw lines for the manage-
ment of the depth.
Thus, fuppofe A B, fig. 3, the vifual ray, whereon the mea-
fures are to be marked ; if you would produce the points C and
D through the fame, do not draw the lines from the point of dif-
tance E, but from that oppofite thereto, F ; or, if C and D were
on