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 concordance
<
1 - 30
31 - 60
61 - 90
91 - 120
121 - 150
151 - 180
181 - 210
211 - 237
>
Scan
Original
31
10
32
11
33
12
34
13
35
14
36
15
37
16
38
39
40
41
17
42
18
43
19
44
20
45
46
47
48
21
49
22
50
23
51
24
52
53
54
55
25
56
26
57
58
59
60
27
<
1 - 30
31 - 60
61 - 90
91 - 120
121 - 150
151 - 180
181 - 210
211 - 237
>
page
|<
<
(15)
of 237
>
>|
<
echo
version
="
1.0RC
">
<
text
xml:lang
="
en
"
type
="
free
">
<
div
xml:id
="
echoid-div54
"
type
="
section
"
level
="
1
"
n
="
26
">
<
p
>
<
s
xml:id
="
echoid-s477
"
xml:space
="
preserve
">
<
pb
o
="
15
"
file
="
0035
"
n
="
36
"
rhead
="
on PERSPECTIVE.
"/>
to the Eye. </
s
>
<
s
xml:id
="
echoid-s478
"
xml:space
="
preserve
">Now, as in the latter Situation,
<
lb
/>
Repreſentatious are drawn upon the Face of the
<
lb
/>
Perſpective Plane next to the Object, the Per-
<
lb
/>
ſpective Plane lying down upon its other Face;
<
lb
/>
</
s
>
<
s
xml:id
="
echoid-s479
"
xml:space
="
preserve
">what ought to be on the Right Hand, appears on
<
lb
/>
the Left; </
s
>
<
s
xml:id
="
echoid-s480
"
xml:space
="
preserve
">and that on the Left, appears on the
<
lb
/>
Right; </
s
>
<
s
xml:id
="
echoid-s481
"
xml:space
="
preserve
">producing exactly the ſame Effect, as
<
lb
/>
looking thro’ the Back-ſide of a Paper, at a Pi-
<
lb
/>
cture drawn thereon.</
s
>
<
s
xml:id
="
echoid-s482
"
xml:space
="
preserve
"/>
</
p
>
<
p
>
<
s
xml:id
="
echoid-s483
"
xml:space
="
preserve
">Yet, notwithſtanding this Deficiency, we pre-
<
lb
/>
fer the latter way of the Perſpective Plane’s ly-
<
lb
/>
ing down to the former, for the following Rea-
<
lb
/>
ſons.</
s
>
<
s
xml:id
="
echoid-s484
"
xml:space
="
preserve
"/>
</
p
>
<
p
>
<
s
xml:id
="
echoid-s485
"
xml:space
="
preserve
">1. </
s
>
<
s
xml:id
="
echoid-s486
"
xml:space
="
preserve
">When the Perſpective Plane lies down in
<
lb
/>
the former manner, it lies upon the Part of the
<
lb
/>
Geometrical Plane wherein Figures have been
<
lb
/>
drawn; </
s
>
<
s
xml:id
="
echoid-s487
"
xml:space
="
preserve
">which, together with the new Lines that
<
lb
/>
muſt be drawn, cauſes a very great Confuſion,
<
lb
/>
and always obliges one to copy his Work. </
s
>
<
s
xml:id
="
echoid-s488
"
xml:space
="
preserve
">An
<
lb
/>
Inconveniency which the latter Method is ſel-
<
lb
/>
dom ſubject to.</
s
>
<
s
xml:id
="
echoid-s489
"
xml:space
="
preserve
"/>
</
p
>
<
p
>
<
s
xml:id
="
echoid-s490
"
xml:space
="
preserve
">2. </
s
>
<
s
xml:id
="
echoid-s491
"
xml:space
="
preserve
">We work with much more Eaſe in the
<
lb
/>
manner I have choſen.</
s
>
<
s
xml:id
="
echoid-s492
"
xml:space
="
preserve
"/>
</
p
>
<
p
>
<
s
xml:id
="
echoid-s493
"
xml:space
="
preserve
">Finally, The Default we have obſerv’d, may
<
lb
/>
ſeveral ways be remedied. </
s
>
<
s
xml:id
="
echoid-s494
"
xml:space
="
preserve
">For, in drawing up-
<
lb
/>
on the Geometrical Plane, we need but place
<
lb
/>
that on the Right Hand which we have a mind
<
lb
/>
ſhould appear on the Left; </
s
>
<
s
xml:id
="
echoid-s495
"
xml:space
="
preserve
">or if the Geometri-
<
lb
/>
cal Plane be drawn upon Paper, it may be oil’d,
<
lb
/>
or dipp’d in Varniſh, which will render it tran-
<
lb
/>
ſparent; </
s
>
<
s
xml:id
="
echoid-s496
"
xml:space
="
preserve
">and then the Back-ſide of the Paper
<
lb
/>
may be thrown into Perſpective.</
s
>
<
s
xml:id
="
echoid-s497
"
xml:space
="
preserve
"/>
</
p
>
<
p
>
<
s
xml:id
="
echoid-s498
"
xml:space
="
preserve
">If all this be not found convenient, the ſaid
<
lb
/>
Default may be eaſily corrected geometrically,
<
lb
/>
in copying the Work after the Drawings are fi-
<
lb
/>
niſhed. </
s
>
<
s
xml:id
="
echoid-s499
"
xml:space
="
preserve
">And this may be yet eaſier done, if
<
lb
/>
the Figures are expoſed before a Looking-glaſs;</
s
>
<
s
xml:id
="
echoid-s500
"
xml:space
="
preserve
"/>
</
p
>
</
div
>
</
text
>
</
echo
>