Journal of
The l ranklin Inslilule D E V O T E D TO
S C I E N C E AND T H E M E C H A N I C
ARTS
EDITOR, H E N R Y B U T L E R ALLEN, M E T . E . D . S c . ASSISTANT EDITOR, JOHN FRAZER, PH.D. ASSOCIATE EDITORS: W I L D E R D. BANCROFT, PH.D. C. B, BAZZONI. PH.D. ARTHUR L. DAY. SC.D. R. E K S E R G I A N , PH.D. A. S. EVE. F . R . S .
H E N R Y C. SHERMAN, S C . D W . F. G. S W A N N , D.SC. HUGH S. TAYLOR, D.SC. A. F. ZAHM, PH.D. JOHN ZELENY, PH.D.
PAUL D. FOOTE, PH.D. W. J. HUMPHREYS, PH.D. C. E. K. MEES, D.SC. W I L L I A M B. MELDRUM, PH.D.
C O M M I T T E E ON P U B L I C A T I O N S : G. H. CLAMER, CHAIRMAN RICHARD HOWSON C. L, JORDAN
L I O N E L F. LEVY MALCOLM LLOYD, J R .
VOL. 2 4 1 . - - N o s .
HIRAM S. L U K E N S RICHARD H. OPPERMANN W I N T H R O P R. W R I G H T
1441-1446
(121st Year)
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PHILADELPHIA Tm~ FRANKLIN INSTITUTE Benjamin Franklin Parkway at 20th Street 1946
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