A great story of debunking fraudsters:

Mr. and Mrs. Tomson were itinerant American music hall artists of comparatively mediocre ability, until taken under the protective wing of William T. Stead, the English editor and journalist. The Tomsons were performing in London when they were first brought to the attention of Mr. Stead by a fellow music hall juggler.

Their act was a fairly clever bit of trickery or sleight of hand, accompanied with all the necessary stage hand assistance. They claimed no mediumistic or supernatural powers for themselves during their early London season, but later they discovered that to be a “spookist” in gullible London meant an augmentation of their financial condition, and added a value to their stage career which in their wildest flights of ambition they had not dreamed of.

[…]

When Sir Hiram Maxim read that his friend William Stead was publicly announcing that he had seen and touched his dead son, Sir Hiram called on Mr. Stead. Their conversation was as follows:

Sir Hiram — Look here, Stead, those spookists are fooling you. You’re too trusting and sincere for those clever rascals.

Mr. Stead — But, Sir Hiram, they showed me my son. Don’t you think I would know Willie?

Sir Hiram — See here, Stead, old fellows like you and Sir Oliver Lodge and myself have no business pronouncing this kind of people genuine. We ought to pass that up to school boys who are full of tricks themselves, or to Americans like the Tomsons, who know more tricks in ten minutes than we do in eight generations…

Mr. Stead — I tell you I saw my son.

Sir Hiram — Swank! You are too honest to catch those tricksters.

Mr. Stead — Then suppose you try.

Sir Hiram — Done! And I’ll make a good job of it, too.

I’ll leave it to you to read how Hiram Maxim exposed the frauds on more than one occasion. Predictably, the Tomsins excuse was that “although the medium really had the power… she could not do so at all times, and sometimes had to ‘fake’ a séance.” This is the same kind of excuse given by so-called psychics today when they are found to be using trickery. See for example Uri Geller.

In this case, Hiram Maxim exposed the Tomsons as frauds enough times that they finally confessed they have never had any supernatural powers of any kind.

SIR HIRAM MAXIM EXPOSES SPIRITUALISTIC MEDIUMS: Noted Inventor Proves Tomsons, Whom William T. Stead Exploited at Private Seances, Were Merely Clever Tricksters. (PDF)

From June 18, 1911