a PY ke
the movements of the plate-holders were successively surveyed within
their complete field: the results are reported in F ig. 12. The six lines
surveyed, 4 border lines and 2 medians, allow on the whole to check the mea-
surements, as they form 4 closed polygons. The error of closure of each poly-
gon is written in the centre of the respective square; the resulting accuracy
E more than sufficient. The value of the anomalous rotations ascertained
Right
| 24
1-83
i: | 8 9? 3 5 9 QA s s £5 5 $ 8
| t ue + EN
1.43
= = LS = - 53 &
pismo o0 3$ | 8 5$ 8 9 EE : pu
1.34 |
La sol 25 d Les
1-22 | 33} |
5 | .52} Ja " i3 10
[ | | I 1 5 09" t=
" . | | * -
= 2] 1.15 .09 25) | 2 i
3 Ï PY „25 7 }-09
„19 {
+ 7 -
a .73| [:02 13
-13 |
9 23] 03 | os 13
La) m - st um 0$ _— = =
es 9 8 = 8h 7 a. SZ o c5 2g Sul a $ 5. 8 5 SL X p S um eU
+= —— - T : 08 ; : CU
EU m a Los
|+03 | |
35 92} a =03 ler
7 . .
3 +07 -26 os 34 +07 E 21 Ie
+16 51 |
35 4M n 1-03
RY |
|o eos -* S5 8 * = 2 S3 gui? 5 fc Lot
| 2 : ecl 2 = 3 a 2 S 3 2 3 = a 3
| +25 m mm ————
| 8 93 u
{= SER
Fig. 12 Values of the plate-holder shifting during its motion
reaches a maximum, between points diagonally opposed, of 22" on the left
camera and of 17'' on the right camera. Considering however that this varia-
tion takes place only with 23 x 23 cm plates, and that a part of the de-
formations of the model due to these rotations can be offset by means
of the orientation elements when determining the zero points of the machine.
the situation following from the fact that the K-swing varies is not excessively
preoccupying.
c) The rod and its Cardan coupling.
In the Stereocartograph the plotting line sight is obtained by means of
à polarly rod mobile about a point which replaces and materializes the prin-
cipal point of the objective. Model IV in particular, in which the plate moves
together with the projection mechanism during plotting, is provided with
à rod which is practically broken down into two parts. The first portion is
the rod proper, and is found outside the camera in the model space; the se-
cond part, the « short rod », is also outside the camera, but over its upper part,
Viz. over the plate. These two pieces are connected with each other by a
robust arm which describes a wide loop outside the camera (see Fig. 2); the
arm is extensible to permit its adjustment to the values of the plotting focal
length.
; Therefore, the theoretic conditions for a correct operation of the project-
Mg system are as follows:
1) straightness of the rod:
9
2) straightness of the short rod and regularity of its motion within the
sleeve connecting it to the arm;
bison irat pe tS ER pr mp etti i
eR RC erre miii hp
MUERE EMT TE EET PU UR E pe er uM e AU p mt EE
RUN ERR S UM LADEN E a rni d E
