i4o SCIENCE PROGRESS 



divining-rod, through phantasms of the living and the dead, telepathy, poltergeist 

 phenomena, direct voice and direct writing, materialisations, and so forth, to the 

 very latest classical conundrums, appreciable only by the learned. Probably this 

 is the best book of all for one beginning the study of the subject. Its general 

 tone is candid and persuasive without being dogmatic. 



Sir William Barrett deals with levitation among other spritualist manifestions, 

 but Dr. Crawford's book is concerned solely with this topic. Levitation is said 

 to occur when a heavy body is raised without the use of any known force, and kept 

 suspended without any visible support counteracting its weight. Dr. Crawford 

 has been fortunate enough to find an unpaid medium who can produce levitation 

 practically at the experimenter's word of command, and he has taken the oppor- 

 tunity to carry out some experiments on more or less scientific lines. He finds 

 that, when the medium is seated on a weighing machine, the table being raised 

 in the air some feet away from her, her weight is increased by nearly the weight 

 of the table, sometimes a little more, sometimes a little less. This taken alone 

 would be interesting, and we might accept the suggestion that, when the added 

 weight is less, a small part of it is borne by other members of the circle acting as 

 accessory mediums. But this, even if it explained anything, would not account for 

 the cases in which the medium's increase in weight is greater than the weight of 

 the table, nor for those in which the medium herself is levitated. And although 

 Dr. Crawford finds no pressure on the floor under the table, yet a scale-pan a few 

 inches above the floor does register a pressure, and sometimes one greater than 

 the whole weight of the table, especially if this is only partly raised, one or two 

 legs remaining on the ground. Again, if the table is levitated from the platform 

 of the weighing-machine, its weight now is found to be on the weighing machine 

 and not on the medium. Sometimes the unseen " operators," as Dr. Crawford 

 calls them, appear to find great difficulty in lifting even a light table ; yet the 

 whole strength of four men is not enough to hold the table down if it is deter- 

 mined to levitate ; and a single man sitting on it is tilted off with the greatest 

 ease. Dr. Crawford is very ready with explanations : in some cases there is too 

 much light, or of the wrong colour, on a part of the apparatus ; or the table is only 

 just small enough to stand on its platform, which is supposed (no reason given) to 

 create difficulty for the spiritual operators. He has also set forth what he calls a 

 theory of levitation, supposing that a flexible or rigid (sometimes it seems to be 

 both at once) rod is formed out of matter taken from the medium and joins her 

 body to the levitated table. Though rigid enough to transmit the weight of this 

 through her body to the weighing machine, it is imperceptible to the touch, nor 

 does she seem to feel any discomfort from the weight so transmitted through her 

 shins, although the table is borne at the end of a lever some feet long. This 

 cantilever theory, with all the accessory explanations, is not by any means con- 

 vincing mechanically. The one point that emerges from Dr. Crawford's measure- 

 ments is that they are hopelessly inconsistent and incomplete. When all these 

 experiments have been repeated with other mediums by other investigators, when 

 there is practical agreement as to the facts, a time may come for spinning 

 theories, but not yet. 



The root of the trouble is here. If in any ordinary inquiry you came upon 

 results like these, the same or another investigator would take the whole thing up 

 afresh from the beginning, with more accurate instrumental equipment, self- 

 recording apparatus, and so forth, and at least make certain of the facts. But in 

 this case that method is not applicable, because the new investigator might quite 

 likely find no facts at all to work upon. Yet, until this question can be cleared up, 



