Smithsonian Report, 1962. —Page 



Plate 4 



1. The X.\F radar (left) and ,1k CXAM radar (ri'-,du). Summer 1940. 



2. Penthouse roof, Bldg. 12, showing (right to left) pre-XAF, XAF, 400-Mc, and CX.Wl 

 antennas. Pre-XAF is hand dri\'en; all others are motor dri\'cn with remote control. 

 Summer 1940. 



