Hudson Pace sent this interesting clipping. He writes:
Here's a hoax (see attached). Presumably done with double-exposures, but it would be nice to know how many people he fooled and why he did it.
It's from 'The Encyclopedia of Modern Wonders for Boys', published by Collins apparently in the 1930s. Googling 'Herbert Winck' gives one reference to the same pictures in 'The Wonder World Encyclopedia' from 1936, also published by Collins. As you'll see from the caption, the pictures fooled at least one person.
I assume the pictures were created via double exposure, in the same way spirit photographs are usually made. As for Herbert Winck, I can't find out anything more about him. But searching the google news archive for articles about invisibility machines, I did come across a March 3, 1937 article in the Chicago Tribune
about an Italian inventor who supposedly created something that sounds very similar to Winck's machine. The article was syndicated. A similar version also ran in the Washington Post
MAKES 2 WOMEN VANISH BY USING A BIT OF SCIENCE
Expert in Physics Insists He's No Magician
Rome, March 2 -- (AP) -- Prof. Mario Mancini, who makes people disappear by "purely scientific principles," insisted today he was not a magician -- and "I do not use mirrors." Mancini, 33 years old and former professor of physics at Breda academy here, made his wife and sister disappear before the eyes of an Associated Press correspondent at his home in Milan. He would not explain beyond saying: "It is simply a scientific instrument which nullifies the rays reflected by opaque bodies."
Uses Wooden Box.
A huge wooden box, of practically cubical shape, the sides of which were about eight feet long, occupied nearly half the drawing room where the professor held his demonstration. The side toward the observer apparently was open but in reality was closed by a sheet of transparent glass. The professor's wife and sister entered the box through a side door and seated themselves in chairs. While Prof. Mancini dangled his legs over the side of a table on which the electrical controls were placed the two subjects inside the box talked to each other and those in the room.
Outlines of Women Vanish
The professor pressed a button illuminating the box inside. Simultaneously there was a distinct buzzing sound. After a few moments the outlines of the two women and the chairs became more and more indistinct until they disappeared completely. The voice of the two still could be heard, however. After another moment the controls were reversed and the two subjects and chairs came back into clear view.