N67/058
23 June, 1967
Mr. J. W. McCormick
Plantsagenet
Ontario
Dear Mr. McCormick:
The substance which you sent to us consists of strips of metal-coated plastic. It has the property that a large cloud of it in the air is a good reflector of radar waves. If dropped by aircraft it will confuse radars and hide them from observation. It comes in small balls that normally break apart when dropped from an airplane. It appears that you caught a piece which had not broken up.
During World War II it came to be called "window" or "cliff".
Yours sincerely,
[illegible]
Bruce A. McLean
Upper Atmosphere Research
[illegible]
NRC
JUG 23 1967
RECEIVED
National Research Council of Canada/
Conseil national de recherches du Canada
RG 77, Vol. 306