220115on PERSPECTIVE.
The Height of the Machine above the Table;
So is
The Glaſſes focal Length,
to the
Diſtance of the Figure from the Glaſs.
So is
The Glaſſes focal Length,
to the
Diſtance of the Figure from the Glaſs.
Note, The ſaid Diſtance of the Convex Glaſs
from the Figure, is meaſured by a Ray, pro-
ceeding from the Figure parallel to the Horizon,
which is perpendicularly reflected upon the Con-
vex Glaſs, by the Mirrour. Note, Moreover, that
when we have a Mind to place the Figures out
beyond the Back-ſide of the Machine, they muſt
be faſtned againſt the Side F of the Board, which
muſt be ſo turned, that the ſaid Side be next to
the Aperture N.
from the Figure, is meaſured by a Ray, pro-
ceeding from the Figure parallel to the Horizon,
which is perpendicularly reflected upon the Con-
vex Glaſs, by the Mirrour. Note, Moreover, that
when we have a Mind to place the Figures out
beyond the Back-ſide of the Machine, they muſt
be faſtned againſt the Side F of the Board, which
muſt be ſo turned, that the ſaid Side be next to
the Aperture N.
37 Remarks concerning the Repreſentation of Per-
ſons Faces.
ſons Faces.
It is certainly very curious and uſeful to de-
ſign Perſons Faces to the Life; which by this
Machine, may be very well done in Miniature:
For if the Face of any known Perſon be thus re-
preſented, by only looking at the Appearance,
we may very readily know whoſe Face it is,
when at the ſame time the Appearance of the
Whole Perſon will not take up half an Inch
upon the Paper on the Table: But it is very dif-
ficult to repreſent a Face diſtinctly as big as the
Life; for when we would repreſent a Face in its
natural Bigneſs, ſuch a Convex Glaſs as is men-
tioned in Numb. 35. muſt be uſed, and the Face
placed where the Board F is . But the 1135. Face which then appears diſtinct enough, that ſo
the Perſon whereof it is the Repreſentation may
thereby be known, hath not its Lineaments ſuffi-
ciently enough repreſented, as to be followed by a
Painter as they ought, in order to keep the true
ſign Perſons Faces to the Life; which by this
Machine, may be very well done in Miniature:
For if the Face of any known Perſon be thus re-
preſented, by only looking at the Appearance,
we may very readily know whoſe Face it is,
when at the ſame time the Appearance of the
Whole Perſon will not take up half an Inch
upon the Paper on the Table: But it is very dif-
ficult to repreſent a Face diſtinctly as big as the
Life; for when we would repreſent a Face in its
natural Bigneſs, ſuch a Convex Glaſs as is men-
tioned in Numb. 35. muſt be uſed, and the Face
placed where the Board F is . But the 1135. Face which then appears diſtinct enough, that ſo
the Perſon whereof it is the Repreſentation may
thereby be known, hath not its Lineaments ſuffi-
ciently enough repreſented, as to be followed by a
Painter as they ought, in order to keep the true
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