Bauhaus-Universität Weimar

Optic Projection: Principles, Installation and Use of the Magic Lantern, Projection Microscope, Reflecting Lantern, Moving Picture Machine
Gage, Henry Simon and Henry Phelps Gage
Ch. XIII] 
Fig. 292. The Vertical Carbon Arc with 20 Amperes of Direct 
a Vertical carbons with the positive carbon above and the negative carlxm 
below. This shows that the large crater is on the positive carbon and the small 
Crater on the negative carbon. Between the two craters extends the arc stream 
of hot gases. 
This photograph was made with an exposure of 1/100 second, the aperture 
b>eing F/22. A color screen was used to cut out most of the violet, so that the 
^.rc stream would not obscure the craters. A subsequent exposure of 90 seconds 
■Was made without a color screen and with an aperture of F/8. The illumina¬ 
tion during this exposure was by means cf a 40 watt, mazda lamp. 
b Vertical carbons with a 20 ampere direct current. No color screen. 
Expo sure 1/100 sec.; opening F/22. 
This shows the size of the two craters; it also shows the conical arc stream 
almost as light as the craters. This is because the violet light which has 
relatively little effect in illumination has a great effect on the photographic 
This picture shows how the carbons, the craters and the arc stream appear 
in an instantaneous view to the photographic plate, while the one at the left 
(a) gives much more nearly the appearance to the human eye with an instan¬ 
taneous view.


Sehr geehrte Benutzer,

aufgrund der aktuellen Entwicklungen in der Webtechnologie, die im Goobi viewer verwendet wird, unterstützt die Software den von Ihnen verwendeten Browser nicht mehr.

Bitte benutzen Sie einen der folgenden Browser, um diese Seite korrekt darstellen zu können.

Vielen Dank für Ihr Verständnis.