Sept. 18, 1885.] 



KNOWLEDGE ♦ 



Miss Ballin, in commenting on the mistake I in nh m 

 substituting the sun for llie earth, ^\hen dcihuL: w uli tli 

 question of the ruddy solar eclipse, tells of an ni ii k ilm 

 case in which Trousseau, after carefully -weighing the 

 question whether he would or would not give a patient 

 belladonna, as usual, for a particular ailment, and deter- 

 mining that he would not, nevertheless wrote out the 

 usual prescription and gave it to the patient in perfect 

 unconsciousness that he was not carrying out his purpose. 



One of the oddest cases of the kind which has ever 

 occurred to me in literary work happened when I was 

 correcting one of the earliest sheets of my first book — 

 " Saturn and its System." I was describing Keiiler's dis- 

 covery of his third law, as illustrated by the periods and 

 distances of Saturn and the Earth. After representing 

 the distance and period of the earth, both, by unity, and 

 so getting two numbers, one representing the distance the 

 other the period of Saturn, I went on to consider tlie 

 power of these numbers as follows, — " The first is less 

 than the second, but the square of the first is greater 

 than the second ; let us then try the square of the second ; 

 — the square of the first is less than the square of the 

 second, but the next or third power of the first is equal 

 to the square of the second : here then is the law we are 

 seeking " or words to that effect. All this was correctly 

 printed. Reading a review of the book in the Quarterly 

 Journal of Science, I found the author of the 

 review asking what I could possibly mean by 

 saying of the above-named numbers "The first is less 

 than the second ; but the square of the first is greater 

 than the square of the second," — which is obviously 

 unmitigated nonsense (or as a friend described an 

 article of mine the other day, " unparalleled rot "). 

 I turned to the passage, and there was the prepos- 

 terous statement. Now in those days, being but a 

 beginner, I had kept the proofs and revises of my 

 book with exemplary care. I turned therefore to 

 these. And I found this startling thing : — I had 

 deliberately corrected the first proof, in which the 

 matter had been quite correctly stated, into the absurdity 

 criticised. If I had originally written that nonsense, 

 and passed it in proof and revise, I should not have 

 wondered, — or at any rate I should not now wonder, 

 knowing what can be done in that way. But to take the 

 correct statement and deliberately alter it into nonsense, 

 was surely a strange thing for the abstracted mind to do. 



In my " Transits of Venus " I wrote, and corrected in 

 proofs and double revises, "seconds" for "minutes," 

 throughout ten or twelve pages, in regard to the most 

 important time-elements in the whole problem of deter- 

 mining the sun's distance from transit observations, — viz., 

 the ditl'erence of duration of the transit for the Halleyan 

 method, and the difference in the times of beginning and 

 ending for the Delislean. 



Professor Kaiser of Loyden dealing with the 

 period of Mars with exceptional care, and co 

 y detail, even to some not capable of affecting I 



by the 



iidth of a second, made t w 



agreement, through a mistake in d: 



ill I \\(iiiM lie ashamed 

 two calculiitions into 

 viding by tiro. 



fe^^B 



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H STAMPED 



PRACTICAL WORK FOR SCIENCE-STAMMERrN'G-INSTRU- 

 MENTAL MUSIC. 

 [1925]— You open your columns to all comers who have anything 

 to say bearing on practical matters. Permit me a word. First, as 

 regards stammering. There are advertisements to be met frequently 

 from persons wlio undertake to cure stammering. But let any one 

 go to tliese and sav, " I wished to be cured, name your price, to be 

 paid on completion of cure. I will deposit the money with some 

 trustworthy person. I am most anxious to be cured, and will follow 

 minutelv all your directions," what will the answer be ? Hemming 

 and hawing, and shuffling. Stammering is greatly on the mcrease. 

 Why will not scientific men take the matter in hand 1 Any man 

 who could realli/ cure this disease would be able to retire in a few 

 years with a large fortune. I know several men, to whom money is 

 no object, who would give large sums to be cured of stammering; 

 but, then, it must be a cure. Second, as regards instrumental 

 music, manv men, having had neither time nor opportunity in their 

 youth to study music, are anxious, as leisure comes to them, to shine 

 later in lite— say from twenty-five to forty-five— to play some in- 

 strument. They begin to practise, but the hand does not answer 

 the brain. The theory is easily acquired, but the joints and liga- 

 ments of the fingers, hand, and wrist are stiff and disobedient. Is 

 it impossible to bring scientific aid to bear here 1 I have been told 

 that eight hours' a day practice for ten years would produce the 

 required result ; wliat we want is an hour or an hour-and-a-half for 

 a twelvemonth to enable us to join in a quartett or sympliony party. 

 Flexibility of finger and strength of muscle must be obtained ; if 

 tliis can "be assisted by science, the rest is easy. I have taken 

 Knowledge from tlie beginning, and have seven handsome volumes 

 on mv shelf of interesting and useful matter. I wiU miss greatly 

 the weekly issue ; but I hope the monthly one will be as successful 

 as its predecessor. 



KOLOKOL. 



THE OCrLAR SPECTRA. 



)t preoccupied 

 e so long and 



[19271— It maybe interesting to some of your readers to know 

 tliat, during a downpour of rain on Thursday, 3rd insf ., a very thick 

 shower of small snails fell with it, in Pembroke Dockyard. They 



