Gravesande, Willem Jacob 's
,
An essay on perspective
Text
Text Image
Image
XML
Thumbnail overview
Document information
None
Concordance
Notes
Handwritten
Figures
Content
Thumbnails
page
|<
<
(29)
of 237
>
>|
<
echo
version
="
1.0RC
">
<
text
xml:lang
="
en
"
type
="
free
">
<
div
xml:id
="
echoid-div107
"
type
="
section
"
level
="
1
"
n
="
59
">
<
p
>
<
s
xml:id
="
echoid-s770
"
xml:space
="
preserve
">
<
pb
o
="
29
"
file
="
0057
"
n
="
62
"
rhead
="
on PERSPECTIVE.
"/>
drawn to the Point G, will give the Appearance
<
lb
/>
ſought.</
s
>
<
s
xml:id
="
echoid-s771
"
xml:space
="
preserve
"/>
</
p
>
</
div
>
<
div
xml:id
="
echoid-div109
"
type
="
section
"
level
="
1
"
n
="
60
">
<
head
xml:id
="
echoid-head62
"
xml:space
="
preserve
">
<
emph
style
="
sc
">Remarks</
emph
>
.</
head
>
<
p
>
<
s
xml:id
="
echoid-s772
"
xml:space
="
preserve
">When this Method cannot be us’d, the Per-
<
lb
/>
ſpective of the Diviſions dividing the Sides of
<
lb
/>
the Parallelogram, mufl be found . </
s
>
<
s
xml:id
="
echoid-s773
"
xml:space
="
preserve
">And we
<
note
symbol
="
*
"
position
="
right
"
xlink:label
="
note-0057-01
"
xlink:href
="
note-0057-01a
"
xml:space
="
preserve
">44.</
note
>
often oblig’d to have recourſe to this Expedient,
<
lb
/>
notwithſtanding the accidental Points, G and F,
<
lb
/>
being had. </
s
>
<
s
xml:id
="
echoid-s774
"
xml:space
="
preserve
">And this happens, when the Paralle-
<
lb
/>
logram is ſo far diſtant from the perſpective
<
lb
/>
Plane, that its Sides being produc’d, cannot meet
<
lb
/>
the Baſe Line.</
s
>
<
s
xml:id
="
echoid-s775
"
xml:space
="
preserve
"/>
</
p
>
<
p
>
<
s
xml:id
="
echoid-s776
"
xml:space
="
preserve
">47. </
s
>
<
s
xml:id
="
echoid-s777
"
xml:space
="
preserve
">Note, moreover, that this one Example
<
lb
/>
is ſufficient to ſhew how to throw any Kinds of
<
lb
/>
Figures in the Geometrical Plane into Perſpe-
<
lb
/>
ctive. </
s
>
<
s
xml:id
="
echoid-s778
"
xml:space
="
preserve
">To effect which, we circumſcribe any
<
lb
/>
Parallelogram about the Figures, which we di-
<
lb
/>
vide into ſeveral others: </
s
>
<
s
xml:id
="
echoid-s779
"
xml:space
="
preserve
">Then we throw this
<
lb
/>
Parallelogram (thus divided) into Perſpective,
<
lb
/>
and transfer the given Figure therein, ſo that it
<
lb
/>
may have the ſame Situation with reſpect to
<
lb
/>
the little Parallelograms in the perſpective Plane,
<
lb
/>
as it had in regard to the ſmall Parallelograms
<
lb
/>
in the Geometrical Plane.</
s
>
<
s
xml:id
="
echoid-s780
"
xml:space
="
preserve
"/>
</
p
>
</
div
>
<
div
xml:id
="
echoid-div111
"
type
="
section
"
level
="
1
"
n
="
61
">
<
head
xml:id
="
echoid-head63
"
xml:space
="
preserve
">
<
emph
style
="
sc
">Example</
emph
>
III.</
head
>
<
head
xml:id
="
echoid-head64
"
style
="
it
"
xml:space
="
preserve
">48. To throw a circle into Perſpective.</
head
>
<
p
>
<
s
xml:id
="
echoid-s781
"
xml:space
="
preserve
">The Repreſentation of ſeveral Points of a
<
lb
/>
<
note
position
="
right
"
xlink:label
="
note-0057-02
"
xlink:href
="
note-0057-02a
"
xml:space
="
preserve
">Fig. 16.</
note
>
Circle, or any other Curve Line requir’d to be
<
lb
/>
thrown into perſpective, muſt be found,
<
note
symbol
="
*
"
position
="
right
"
xlink:label
="
note-0057-03
"
xlink:href
="
note-0057-03a
"
xml:space
="
preserve
">21.</
note
>
may be well enough done, by drawing ſeveral
<
lb
/>
Chords in the Circle, or Curve, parallel between
<
lb
/>
themſelves, the Repreſentations of which muſt
<
lb
/>
be found ; </
s
>
<
s
xml:id
="
echoid-s782
"
xml:space
="
preserve
">then the Extremities of thoſe
<
note
symbol
="
*
"
position
="
right
"
xlink:label
="
note-0057-04
"
xlink:href
="
note-0057-04a
"
xml:space
="
preserve
">43.</
note
>
</
s
>
</
p
>
</
div
>
</
text
>
</
echo
>