can use the 
pe of stereo- 
one has — 
rs and other 
' can analyse 
se, basically 
ography can 
n insofar as 
X-Ray pho- 
ious growths 
veral defects 
mal photog- 
olution. The 
sion with X- 
ids to a loss 
rity of point- 
dly, there is 
a change of 
'hich the X- 
>ctive which, 
ther than the 
a lens. 
both surface 
1edical cases 
mmetrically. 
d from my 
ould assume 
uitable plot- 
is somewhat 
ment by ad- 
> of carrying 
y apparatus 
r conditions 
those which 
ogrammetry. 
king on this 
ifacturers to 
ace photog- 
surface pho- 
cise plotting 
n economic 
of the infor- 
pe recorded 
country, for 
| singly and, 
would have 
ospitals and 
to have en- 
DISCUSSION ON X-RAY PHOTOGRAMMETRY 7 
couraged some manufacturer to produce a 
simple plotting instrument restricted possibly to 
photographs which are taken in a co-planar 
condition and to photographs taken under con- 
ditions of known base and known orientation. 
Herr Professor BURKHARDT: Ich danke Herrn 
Kollegen Miskin für seine überzeugenden Aus- 
führungen und darf um weitere Wortmeldungen 
zu diesem Thema zunächst bitten. 
Prof B. HALLERT: As with all kinds of 
photogrammetry we have to go ahead with 
orientation, to investigate systematic disturb- 
ances in the central perspective, etc, and in this 
respect there are certainly radial distortion ef- 
fects, condition distortion effects and many 
other things like that which we have to take up 
further before we can go ahead with measure- 
ments. 
Perhaps it might be possible later on to 
demonstrate a few results of such investigations, 
founded upon principles which are exactly the 
same as if you are working with any kind of 
photographs. Also the parallax method can be 
used to a great extent to determine basic errors 
of X-Ray photography, and I think we can also 
use this method to determine the resolving 
power which is of basic importance for the 
localisation of details, in particular perhaps to 
be sure that we have the same details in both 
Archives 6 
photographs which we are measuring. We have 
there again that extra condition which we have 
free of charge, which we should take into ac- 
count, the condition that the rays should intersect 
again. 
Herr Professor BURKHARDT: Ich danke Herrn 
Kollegen Hallert verbindlichst fiir seine weite- 
ren Ausfiihrungen und ich glaube, die scheinen 
zu beweisen, dass es hier doch zu einer recht 
erfolgreichen Zusammenarbeit kommen kann, 
wenn man die verschiedenen und verschieden 
gerichteten Arbeiten einmal in einem Haupt- 
thema zusammenfassen kann. Ich möchte nun 
noch zum Schluss sagen, dass es uns höchst 
willkommen ist, wenn wir vielleicht schriftlich 
oder mündlich noch weitere Vorschläge für 
künftige Themen bekommen, sodass wir für den 
Sonnabend dann schon vielleicht am Freitag ein 
Programm verkünden können. Damit hoffe ich 
für heute genügend Stoff zum Nachdenken ge- 
boten zu haben, und ich möchte Ihnen einige 
wenige Minuten von denen zurückgeben, die 
Ihnen vorher für die längere Sitzung verloren 
gegangen sind. Damit darf ich diese Sitzung 
schliessen. 
The discussion on this subject was continued 
in the Meeting held on Friday, 9th September, 
see page 26.