May 18, 1883.] 



♦ KNOWLEDGE ♦ 



299 



The best public exponent of penuine thougbtreading is a young 

 Wesleyan minister, Rev. K. U. Sugilen, B.A. This gentleman also 

 illustrated I'rofeSBOr Thorpe's lecture, and discovered, blindfolded, 

 the number of a bank-note, and wrote on a black-board a word 

 thought of, but ii"( spoken, by the person whose hand he held. I 

 shoald bo glad to hear of well-authenticated cases of thonpht-read- 

 ing u'ilhout contact, of which we hear bo much, and to which the 

 usual explanation of unconscious muscular action could not bo 

 applied. Willing. 



PROBLEM IN CHANCE. 



[818] — A short time back you had in Knowledge some papers 

 on probabilities and chances, and I should like to put before you 

 rather an interesting example, and should be glad if you would 

 inform me how to correctly solve it. 



The editor of the Sporting Times is issuing a new paper called 

 The Prize If'inner, in which he offers certain prizes for picking a 

 certain number of winning horses out of ten given races, as a bait 

 to subscribers. The chief prize is JEIOO for picking all the ten 

 winners. Now, if we say there are five horses in each race to pick 



from, is. not the chance of picking all the ten only ^ or 



o «/,7t)D,o^5 r 



If the £100 is not taken, there is another prize for picking five 

 winners or more out of the ten races — let us say, six winners out 

 of ten races. 



Now, to pick six winners out of six races, in each of which there 

 are five horses to pick the winner from, the chance here would be 



may be picked, the chance of naming the six is increased, and in 

 what wav to arrive at the actual increase here, I do not know. 



A. M. T. 

 [I leave the problem for a week or two, as an exercise for our 

 readers, noting only that in all such cases the offerer of tho prize 

 takes a tremendous advantage of subscribers. — R. P.] 



LOGICAL PUZZLEDOM. 







I I 



[819] — I think you are too hard on the logicians, both in what 

 yon (apparently) expect them to do and in your comments on what 

 they have done. 



The puzzle which you really set them is this : To exhibit syllo- 

 gistically a piece of reasoning which is purely arithmetical, and to 

 do this in a single syllogism (at all events, I can anticipate the 

 comments which you would make if I sent you three or four syllo- 

 gisms, the last of which led to the conclusion in question), without 

 expressing the arithmetical axioms assumed. If logic cannot do 

 this (or finds great difficulty in doing it) yon conclude it to be 

 worthless. 



Now, Sir, in the first place, no logician, I believe, contends that 

 all reasoning is, or ought to be, reduced to syllogistic form. What 

 he contends is that all right reasoning can be reduced to one or 

 more syllogisms, and that, therefore, when we have discovered tho 

 tests which distinguish good from bad reasoning in syllogisms (such 

 as, for instance, imdistributed middle, illicit process, or ambiguous 

 terms), we can apply these tests to ordinary reasoning without 

 actually performing tlie reduction. To show that logic is useless, 

 it should be shown either that these tests are useless, or that men 

 spontaneously apply them without any logical training. 



But, in the second place, all logicians, I believe, admit that the 

 reduction of ordinary reasoning to syllogistic form must be left to 

 the reasoner himself, and that no cut-and-dried rules can be laid 

 down for its performance. To which I may add, that while some 

 simple and obvious arguments require a good deal of trouble in 

 ndnction, other arguments which are by no means simple can be 

 reduced to syllogistic form without difficulty. You will not, I 

 think, find much difficulty in ttiming the following argument into 

 a syllogism : — The universe is constantly p.irting with its heat ; 

 for it is radiating it away into the space which surrounds it, and 

 the greater part of this radiant heat, meeting with no solid body in 

 Ha path, never returns. But is this reasoning correct ? I think 

 Jon will not find it easy to give an answer. 



W. H. S. MoxcK. 



[I merely said that, without any training in formal logic, the par- 

 ticular relation presented by Professor De Jlorgan ought to be 

 obvious. The falsity of the reasoning at the close of our corre- 

 spondent's letter lies in the assumption that the universe is sur- 

 xoonded by space, which is no more correct than would be the 

 assumption that space is surrounded by the universe. The broad 

 fact that among the ablest reasoners the world has known, nine out 

 of ten have known nothing of formal logic, or, knowing its rules, have 

 never thought of applying them, is that on which I would alono dwell 



in discussing the value of the study of logic. Yet in its proper 

 place, and in proper degree, the study of logic is excellent for the 

 mind, precisely as the study of mathematics is good even for those 

 who never care to nso mathematics in their actual studies. — R. P.] 



ALTERATION IX COAST LINE AND SUBMERGED 

 FORE.STS. 



[820] — As supplementing and correcting some statements by 

 " H'sett" (7C8), p. 183, allow me to say that on the NE coast of 

 Sheppey tho rate of waste is about a quarter of a mile in a century, 

 not 3ft. I can advance proof that during the last 300 years tho 

 line of cliff has receded three-quarters of a mile. 



Warden Church was pulled down some years ago, w^hen its posi- 

 tion became dangerous, and during this last winter its site and the 

 whole of the graveyard have slipped away. Before long, on the 

 beach below, human remains will be as plentiful as fossils. 



Minster Church and village are now little more than a quarter of 

 a mile from the sea, so that in another 100 years these will pro- 

 bably be swept away, unless in tho meantime the process of waste 

 bo stopped by an embankment. 



Will " H'sett" state what evidence there is of an ancient forest 

 having been discovered below tho surface at Sheerness ? Drift 

 timber is plentiful enough in the London clay, and may also occur 

 in tho alluvium which — 60 or 70 ft. thick — overlies this at the spot 

 indicated ; but di'ift timber in a sedimentary deposit is a very 

 different thing from a submerged forest, indicating an old land 

 surface. 



Tho skull of the enormous turtle (Chehne gigas), which I found 

 some time ago, is now in the Natural History lluseura at South 

 Kensington. W. H. Shrcbsole. 



HOW TO USE THE EYES. 



[821] — Like yourself, I am particularly interested in this ques- 

 tion, and hope to see it fully discussed in the pages of your valu- 

 able .Journal. The points I msh to refer to, however, will hardly 

 come within the province of the author of the above papers to deal 

 with, and it may not be out of place for me to seize the opportu- 

 nity — suggested by your note appended to a letter by " Myopia" 

 — of stating a case, which, although it may be rather a side-issue, 

 may yet have some claim to come under the subject of " How to 

 use the eyes." It is this, that, as in your own case, I have one 

 eye much more short-sighted than tho other, and that I see double. 

 But the ordinary position of one of my eyes is what is known as 

 an outward " squint," and it is only when I bring this eye to 

 look straight with the other that I have double and also indistinct 

 vision. 



Of course, any one may at pleasure so adjust his sight as to see 

 double, but the question is, how is it that in this case double vision 

 is always the result of this experiment ':" If an oculist were to 

 operate and correct the squint, wonld the result be double and 

 indistinct vision ? This would be an important consideration, and 

 as I have often wished to have the operation performed, perhaps 

 some of your correspondents who may bo able to speak with the 

 authority of experience in the matter, will kindly give me their 

 opinion. 



There may be many cases similar to my own, and of course the 

 correction of such a defect would be a great advantage to the indivi- 

 dual concerned ; but before tampering in any way with the eyes, let 

 us bo certain, as far as j>ossible, of results, I have been advised on 

 both sides — for and against the operation — by medical men, some 

 years ago, but would now like to have the testimony of any one 

 who may have had such a case brought under his notice. 



Oculcs. 



WART-CHARMING. 



[822] — I am not a believer in any one of the occult " sciences." 

 I am of opinion that many extraordinary things, when sifted, 

 would prove to have no better basis than a garbled account of some 

 actual fact, totally different and altogether unimportant ; but what 

 am I to make of this ? A gentleman now sitting before me, whose 

 mind is as sceptical as my own, tells me that five-and-thirty years 

 ago, when he was about fifteen years of age, his hands were un- 

 sightly from warts. When out for a walk with his father he 

 called upon an acquaintance, who noticed them, and said that if he 

 would call upon him during tho week he would remove the warts. 

 The youth went, and was told to sit down and count his warts. 

 Some were partially grown together, and he put the question 

 as to whether he was to count them as one, or two, or three, 

 as the case might be. The answer, somewhat abruptly given, 

 was, that he must count his warts, and say how many he 

 thought he had. The "charmer" left the room for a minute, 

 came back, asked for the number, and told the youth that would 



