H.g. Wells 
The Chronic Argonauts 

There is absolutely no deception, sir, said Nebogipfel with the slightest trace of mockery in his voice. ‘I lay no claim to work in matters spiritual. It is a bona fide mechanical contrivance, a thing emphatically of this sordid world. Excuse me — just one minute.’ He rose from his knees, stepped upon the mahogany platform, took a curiously curved lever in his hand and pulled it over. Cook rubbed his eyes. There certainly was no deception. The doctor and the machine had vanished.