US3101472_page_5

US3101472 | page 5 | https://thedailydialectics.com/pdfs/wipow/US3101472/US3101472.pdf

8,101, 472... change © the direction of the beam by means of reflecting : metal plates. A further. object. of the invention is to enclose the beam wavegitide in a tube: of -preferably non-conducting material ‘such:!as.concrete and to bury. it underground. These ‘and ‘other objects of the invention.…