The Time Eliminator

Kaw (also Kaw Kaw: pseudonym?). "The Time Eliminator." Amazing, December 1926. Available as a Kindle edition.[1] Discussed in Stephen Baxter's "The Technology of Omniscience: Past Viewers in Science Fiction," our initial source for this citation.

"Author's [?] Note" headnote asserts that if Albert Einstein turns out to be wrong about nothing moving faster in our universe than light, then "Perhaps it IS possible to catch up with the light rays that have gone into the beyond. If it is possible to do so, we should be able to photograph or throw on a screen at some future date how Columbus actually discovered America, and other famous historical events. At any rate, THE TIME ELIMINATOR demands your attention. A very clever explanation is go en of a wonderful apparatus that does it all [...]" (Kindle sample on line 18 March 2019, italics removed).

The apparatus is a home-lab-built gadget "'like a modern radio combined with a motion picture machine'" (quoted in Baxter, p. 101). After viewing a couple historical events, it occurs to the inventor to contact the U.S. government's secret intelligence service and offer the device for spying. See for a relatively innocuous, fairly early use of electro-mechanical surveillance.

RDE, Initial Compiler, 18Mar19