5124An ESSAY
thod, unleſs by Means of the Point A, the Ap-
pearance of ſome other Point taken at Pleaſure
upon the Geometrical Plane be found, by Means
of which, the Appearance of the Point B may
be afterwards gotten; but in theſe Caſes, the
ſhorteſt Way, is to uſe ſome one of the precedent
Methods.
pearance of ſome other Point taken at Pleaſure
upon the Geometrical Plane be found, by Means
of which, the Appearance of the Point B may
be afterwards gotten; but in theſe Caſes, the
ſhorteſt Way, is to uſe ſome one of the precedent
Methods.
Corollary.
38.
It appears from this Method, that when
the Repreſentations of two Points are found,
the Appearance of any third Point whatſoever
may be had, without having any Regard to the
Situation of the Eye; becauſe two Lines as E a
may be drawn, whoſe Interſection will be the
Point ſought.
the Repreſentations of two Points are found,
the Appearance of any third Point whatſoever
may be had, without having any Regard to the
Situation of the Eye; becauſe two Lines as E a
may be drawn, whoſe Interſection will be the
Point ſought.
Method VI.
39.
The ſame things being given, as in the
11Fig. 12. ſecond Method, let F C be the Geometrical Line.
11Fig. 12. ſecond Method, let F C be the Geometrical Line.
Operation.
Draw two Lines A F and A C from the given
Point A at Pleaſure, cutting the Baſe Line in the
Points E and B, and interſecting the Geometri-
cal Line in the Points F and C. From theſe
two laſt Points draw the Lines F O and C O to
the Eye; then draw E a through the Point E,
parallel to F O, and B a through the Point B,
parallel to C O, and the Point a the Interſection
of theſe two Lines will be that ſought.
Point A at Pleaſure, cutting the Baſe Line in the
Points E and B, and interſecting the Geometri-
cal Line in the Points F and C. From theſe
two laſt Points draw the Lines F O and C O to
the Eye; then draw E a through the Point E,
parallel to F O, and B a through the Point B,
parallel to C O, and the Point a the Interſection
of theſe two Lines will be that ſought.
Note, We might firſt have drawn the Lines
O F and O C at Pleaſure, and then have drawn
the Lines AC and A F through their
O F and O C at Pleaſure, and then have drawn
the Lines AC and A F through their