What scientist invents the resonator in Lovecraft's 'From Beyond'?

Crawford Tillinghast invents the resonator in Lovecraft’s “From Beyond.” The unnamed narrator visits Tillinghast, a scientist researching the boundaries between physical and metaphysical reality, and witnesses the machine’s terrifying effects.

The device emits a resonance wave that stimulates the pineal gland, allowing people to perceive planes of existence normally hidden from human senses. Once activated, it reveals translucent creatures occupying a dimension overlapping ordinary reality. Tillinghast also discovers that the process works in both directions: the entities can see and attack humans.

The story was written in 1920 but first published in The Fantasy Fan in June 1934. Readers sometimes confuse the short story with Stuart Gordon’s 1986 film adaptation, which changes the setup: the film makes Crawford Tillinghast an assistant to Dr. Edward Pretorius, the scientist who develops the Resonator. In Lovecraft’s original story, Tillinghast himself creates and operates the machine.