632 Transactions of the American Institute. 



Mr. Young — Mr. Yarley, the celebrated English engineer's account 

 of the phenomena, destroys everything you have said to-night. 



The President stated that Mr. Crookes is still experimenting, and 

 is determined to continue until he can come to a positive conclusion 

 with regard to the cause of the phenomena. Coleman Sellers, of 

 Philadelphia, has replied to Mr. Crookes, and he stated that, judging 

 from the reported weight of the mahogany bar, it must have been 

 hollow ; but Mr. Crookes replied that Mr. Sellers is mistaken as to 

 the kind of mahogany used. 



Dr. Yan der "VVeyde stated that this experiment was only tried 

 once, but suggested that it could easily be performed by electro- 

 magnetism, the pressure of the finger making a connection, through 

 wires concealed in the mahogany bar, with the spring balance, in 

 which an electro-magnet may be concealed. This experiment was no 

 more wonderful than the magic clock, the hand of which Heller causes 

 to move ; yet the latter is easily explained. The clock has two glass 

 faces, and the hand is suspended disconnected from the rim, while the 

 whole is hung from the ceiling by two cords. But the rim of the 

 clock is an electro-magnet, the wires passing through the two cords ; 

 and by using a strong battery the hand will revolve in one direction or 

 the other, according to the direction of the current, or stand still when 

 the current ceases. The magicians are familiar with all such devices. 



Prof. John Phin — There are two questions to consider : one is the 

 question of deceiving our neighbors, and the other is the question of 

 deceiving ourselves. It is easy for a man to move a table, knowing 

 that he is doing it, so as to deceive others ; but there are persons who 

 will move the table not knowing it. To determine this, Prof. Faraday 

 constructed a table with a double iop, and attached an index, so that 

 any force applied by the hands moved the index. He found that 

 whenever the index was in sight of the individual, so that he could 

 know what he was doing, there was no motion. But wdien the index 

 was concealed, after a time the muscles began to act involuntarily, and 

 perfectly honest persons were ready to say that they had exerted no 

 force when really they had exerted it. 



The tricks which can be performed by electro-magnetism are almost 

 endless. A juggler suspended a glass dish cover, with a little hammer 

 attached, to strike as a bell, by a single very fine wire or thread from 

 the ceiling, and the bell sounded as he wished. Of course it was 

 thought there was no electricity about that, because he would need 

 two wires. The fact was that he hcyol two wires, insulated and covered 

 with another fine wire. 



