This feat is another "free advertisement" demonstration, in which the performer, with the permission of the city officials, discovers the location of a certain fire-alarm box, and turns on the alarm with the key which had been previously loaned him. Some public officials allow this test to be performed, using it as a test alarm for the department as well, and the sight and sound of the clanging fire-engines, the smoke, and confusion following upon the sensational Mind Reading demonstration is calculated to cause great excitement and interest in the town, which usually results in packed houses at the night entertainment. But the test is really nothing but a variation of the simple "finding the spot" demonstration, with sensational accompaniments. VARIATIONS. We might enlarge our list of "Sensational feats," but to no real benefit to the student, for they are all cut from the same cloth, and are but "improvements" upon the simple parlor feats. If the student wishes to do so, he may invent a dozen similar feats, just as sensational and just as effective. The purpose of the sensational feat is primarily to gain free advertisements for the public performers. As scientific demonstrations they have but very slight value. "FAKE DEMONSTRATIONS" EXPOSED. In concluding this part of the book, we wish to warn our students against some of the so-called "Mind Readers" who are travelling around the country giving exhibitions of so-called Mind Reading which while interesting enough in themselves are nothing but cleverly devised devices intended to counterfeit the genuine phenomena. The majority of these performers have a series of cleverly arranged "signal-codes" by which the confederate conveys to the "Mind Reader" the name and description of the article handed to the former by some one of the audience. One of the principal performers in this line in this country had a signal-code of over five-thousand objects, which he and his confederate had carefully memorized. This code was worked by the plan of asking the blindfolded "Mind Reader" to name the object. You can see the possibilities of this when you remember the many different ways in which the same question may be asked, and when you remember that each word, and combination of words, conveys a distinct and separate meaning to the blindfolded one.