Propnomicon creates the Tillinghast Device from Lovecraft’s “From Beyond”.
Lovecraft’s devices are perhaps an under-considered part of his work. Off the top of my head I can think of…
* The time travel device and camera-like ray weapons in “Shadow out of Time”.
* The devices of Curwen (“Never before or since had he seen such instruments or suggestions of instruments as here loomed up on every hand through the burying dust and cobwebs of a century and a half”).
* The ‘mechanical’ and ‘canister’ aspects of the ending of “The Whisperer in Darkness”.
* The machines in “Cool Air”.
* The ray-projector in “The Evil Clergyman”.
* The cosmic telepathy device in “Beyond the Wall of Sleep”.
And probably there are others I forget now, and still more that are less central to the plots or to be inferred from the Commonplace Book or even the letters. I don’t recall ever seeing a pure Lovecraft RPG book (as opposed to a ‘Derlethian/wider-Mythos Lovecraft’ RPG book) collecting such things in one volume and giving them gamer stats etc.