Heala Ray infra-red sources with E27 base

Two very old (and lethal-looking!) heat lamps I found on Ebay recently. As some of you may know from browsing my gallery, I have a fair few of these already but perhaps none quite as old as these, which are so old they feature no protective cage over the elements. These lamps came with their original instruction leaflets, both of which are dated to 1939.