A Caltech Library Service

High frequency rays of cosmic origin

Millikan, R. A. (1926) High frequency rays of cosmic origin. Proceedings of the National Academy of Sciences of the United States of America, 12 (1). pp. 48-55. ISSN 0027-8424.

See Usage Policy.


Use this Persistent URL to link to this item:


It was as early as 1903 that the British physicists, McLennan and Burton(1) and Rutherford and Cooke(2) noticed that the rate of leakage of an electric charge from an electroscope within an air-tight metal chamber could be reduced as much as 30% by enclosing the chamber within a completely encircling metal shield or box with walls several centimeters thick. This meant that the loss of charge of the enclosed electroscope was not due to imperfectly insulating supports, but must rather be due to some highly penetrating rays, like the gamma rays of radium, which could pass through metal walls as much as a centimeter thick and ionize the gas inside.

Item Type:Article
Related URLs:
URLURL TypeDescription
Additional Information:Copyright © 1926 by the National Academy of Sciences. Read before the Academy November 9, 1925. Mr. I. S. Bowen, Dr. Russell Otis, Mr. G. Harvey Cameron and myself, all of whom have participated in this investigation and have received invaluable aid from the instrument maker, Mr. Julius Pearson, will publish full details of this work elsewhere.
Issue or Number:1
Record Number:CaltechAUTHORS:MILpnas26
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1449
Deposited By: Tony Diaz
Deposited On:19 Jan 2006
Last Modified:02 Oct 2019 22:43

Repository Staff Only: item control page