I found this listed in an old Westinghouse movie theatre advertisement : https://www.ebay.com/itm/WESTINGHOUSE-Vintage-Movie-Theater-Trade-Ad-1949-Light-Bulb-Advertising-Poster/401834416819?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

I've never heard of a Rectigon , What does it do ? the ad says that the 15 amp Rectigon was "redesigned and improved for longer life ,trouble free service and better performance "

 The add is from 1949 .

I believe a rectigon was basically the Westinghouse version of a tungar bulb, intended as a low voltage, high current rectifier for battery charging, or in this case, supplying high current dc electricity for the carbon arc lamp in the film projector.

Ahhh ! Now I get it. Truthfully I'd never heard of EITHER of them before. Thanks for the information !