File:Motion picture electricity (1914) (14597555177).jpg

Identifier: motionpictureele00hall (find matches)
Title: Motion picture electricity
Year: 1914 (1910s)
Authors: Hallberg, Josef Henrik, 1874-
Subjects: Motion picture theaters Electric lighting
Publisher: New York city, The Moving picture world
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
pper crater, interfering less with the rays of light fromthe upper carbon crater. If you will look again at Fig.101, you will find that the point of the lower carbon isslightly in front of the lower edge of the upper carboncrater, cutting off some of the illumination. This troubleis done away with when setting the carbons as illustratedin Fig. 103. The carbon setting shown in Fig. 103 is extremely diffi-cult to handle, because as the upper carbon burns away, itscrater gradually gets back further and further from thecenter of the lower carbon point, thus making it necessaryto push the upper carbon forward or readjust the uppercarbon clamp so that the upper carbon will be put at agreater angle, in that way pushing its crater forward, orby swinging the lower carbon point backward so as tomaintain the same relative position, as illustrated in Fig.103, between the two carbon points. Expert operatorscan do these stunts, but it is a difficult job and requires a 178 MOTION PICTURE ELECTRICITY
Text Appearing After Image:
MOTION PICTURE ELECTRICITY 179 great deal of judgment and care so as not to interferewith the continuous operation of the light while the pic-ture is being exhibited. The gain by putting the carbons as illustrated in Fig.103 when the alternating current arc is controlled by theordinary means, as already referred to, as compared withthe carbon setting shown in Fig. 101 is not sufficientlygreat to warrant introducing the possible chance of trou-ble by setting the carbons as shown in Fig. 103. There-fore, the carbon setting as shown in Fig. 103 is not rec-ommended for general use with alternating current, ex-cepting in cases where special means of current controlare introduced. This setting is of value, however, wherethe motion picture lamp is provided with the backwardand forward adjustment for the upper carbon, controlledoutside the lamp-house, as is now general in the moremodern motion picture lamp equipment. To further explain the exact distribution of illumina-tion from the craters

Note About Images