OCR Text |
Show Electricity in Signaling The newest use of electric lamps t secret signaling for military purposes. By properly screening signal lamps with certain materials only the Infrared Infra-red rajs, which are invisible to the- r.l..3 ...... . r-l PulaQBA Thrtda II fn M celved at various distances by sensitive sensi-tive apparatus which will sonnd busters bus-ters and otherwise respond to the rays even though nobody In thnt region except ex-cept tha operators Is conscious of the fact that the peculiar light Is being; transmitted. |