KNoWIJlUCli:. 



January. 1912. 



MK. UoHl KISON ixrsiis MK. I'KlK lOK. 

 To the fiililnrs o/ " Knowi.iuigk." 



Sirs. — Many of your rraiU-rs will cjniibllcss hi- iiitercsiti'd to 

 learn that Mr. John M. Uolwrlson. M.I'., in his " Lotlc-rs on 

 KcasnninK." claims to have shown that llu- fonndcr of this 

 jonrnal "falls into pnro alisnrdity" in his exposition of the 

 ni.'ithcniatical theory of rrobahility. I have written to him 

 privately pointing oiil tlial his .irKnment is foumletl on a 

 iihmder due to a earelessness that is very inappropriate in 

 dealing with an eminent man of scienci-. ami nr^^iiifj that his 

 book should lie provitled with an erratum slip doiiiK jnslici' to 

 Mr. Procter; but his reply makes it clear that he intends to 

 leave his book as it sl.inds. and I therefore trust that you will 

 allow me to deal with the matter in your columns. 



In No. \'II of his "Letters" above referred to. Mr. 

 Kobertson cpiotes Mr. I'roctor's statement that in the in.iny 

 thousands of experimental coin tossin^s by HntTon and others, 

 a succession ot twelve he.ids (which fre<ineutly occiUTedl was 

 followed by another head as often as it was followetl by a 

 tail: and he says that, in in<aking this statement, Mr. 

 Proctor was " in effect assertioR that in the given experi- 

 ments runs of thirteen he.ids were exactly as common as 

 runs of twelve, and if his arguincnt were coherent, he 

 w.as committed to arguing that runs of fourteen were 

 as common as runs of thirteen, and so on indefinitely." 

 Now, a moment's consideration ought to show that .Mr. 

 Proctor was simply asserting, in efl'ect, that runs of thirteen 

 or more were as common as runs of twelve; but as Mr. 

 Robertson professes not to see this. I will now make the 

 matter even more simple than I did in my letter to him. 



.'Vceording to Mr. Proctor's statement, it will be seen that if 

 there \vere/oi(r hundred cases in which twelve heads were 

 followed by a tail, there would also be four hundred in 

 which they were followed by a thirteenth head ; and out of 

 the latter four hundred, there would bo txvo hundred in 

 which thirteen heads were followed by a tail, and two 

 hundred in which they were followed by a fourteenth head : 

 .and out of the latter two hundred there would be one 

 hiindreil in which fourteen lieads were followed by a tail. 



and (Uie hundred in which they were followed by a fifteenth 

 head; and s4i on. It is thus clear that Mr. Uobert.sou is 

 altogether wrong when he goes on to say that Mr. Proctor's 

 statement implies that runs of a thousand would be ns 

 coumion as runs of three; and I trust he will now admit th.at 

 his supposed proof of Mr. Proctor's "pure absurdity" is 

 founded on a misunderstanding of his own. 



H,AV„ON.nN--TVNE. '''■ '• "^■^•■'"*•^■• 



Till 



Sl'N .\NI) I 



i;iKi:cT ON Nir.M.nv. 



To the Editors of " KNowi.F.Dr.i:.' 



Sirs, — Perhaps the following may be of interest to some of 

 yoiu' readers : — 



Not long :igo .Mr. Tillemont Thomson, lecturing at 

 l-iverpool, said he believed that there was no heat at all 

 in the sun, and never h.as been. He supposes the sun to 

 bo the source of, or to have stored up in it. an incalculable 

 amount of some kind of energy, and that part of this is 

 transmitted through the ether and when it meets our 

 atmosphere is transformed and produces what we know as 

 heat. 



If such be true, then, as there are various kinds of ether 

 waves just .'is there are various forms of matter in existence. 

 is it not possible that there conies from the sim some other 

 kinds of unknown ether waves which have a direct effect on our 

 vitality ? My reasons for supposing such are that, as every one 

 knows, during the early hours of the mirning, when the sun 

 is on the other side of the earth, our vitality is at its lowest, 

 and is the time when most people die ; moreover, this is not 

 due to the effect of the lowered temperature at that time, it is 

 due to something outside all that, because even if these con- 

 ditions are counteracted for by artificial means, the vitality is 

 lowered still to a certain extent. We know that electricity 

 has an effect on our bodies and nervous systems, and that 

 ether waves affect material substances, so could there not be 

 some ether waves having effect on our vitality ? 



' C. POTTF-R. 



BlRKR.SHKAD. 



ANNOUNCEMENTS. 



C"L.\SSn:S IN PHOTOCR.APHY.— We are asked to 

 announce that Mr. Kdgar Senior's classes in Photography for 

 the winter session, will open at the following Polytechnics on 

 the dates specified: Battersea, Tuesd.ay, January 9th ; South 

 Western, Monday, January 15th and Woolwich, Wednesday, 

 January 10th. 1912. 



I LLr M 1 N .-\TI NG KNC. INEKRI NG.— On Friday, January 

 12th, Mr. J. S. Dow, O.Sc will begin a course of Lectures 

 dealing with the measurement of light : the comparison of d.iy 

 and artificial light ; and practic.il lighting problems : at the 

 Battersea Polytechnic. 



PALAFOBOT.ANV.— On January 16th, 1912, and on the 

 nine following Tuesdays, at 4 p.m.. Miss Marie Slopes, Ph. P., 

 D.Sc, will deliver a scries of Lectures in University College, 

 London, on " General and Geological aspects of Palaeo- 

 botany." The course is intended for students of Geology, 

 Botany and Mining Engineering, and the fee is one guinea. 



ROV.\L INSTITUTION.— .\ Genend Meeting of the 

 Members of the Royal Institution was held on the 4th instant. 

 Sir J:unes Crichton Browne, Treasurer and Vice-President, in 

 the Chair. Miss Goldsmid. Pr. Habibur Rahman Khan, Dr. 

 W. M. Noott, and Mrs. Middleton Robinson were elected 

 Members. Professor W. C. Brilgger (Christianiai, Geh. Kath 

 Professor T. Curtius (BerlinI, Professor P. A. Guye (Geneva), 

 and Geh. Regiersrung Rath Professor H. Rubens (Berlin), 

 were elected Honorary Members of the Royal Institution. The 

 Chairman aimounced that the Managers .at their Meeting held 

 this day. h.ad appointed Mr. W. Bateson, .M.n„ r.R,S., 

 I'ullerian Professor of Physiology for a term of three years. 

 The following .arc the Lecture Arrangements .at the Royal 



Institution, before Easter : — Dr. P. Chalmers Mitchell, a 

 Christmas Course of Six Illustrated Lectures on The Child- 

 hood of .Animals, adapted to a Juvenile .Auditorv-: 1. Intro- 

 ductory : 2. The Duration of Youth ; 3. Colours and P<atterns 

 of Young Animals : 4. ^'oung .Animals at Home : 5. The 

 Feeding of Young .Animals ; 6, The Play of ^oung -Animals. 

 Mr. W. Bateson, I'ullerian Professor of Physiology, R.I.. Six 

 Lectures on The Study of Genetics. Professor E. G. Coker. 

 Two Lectures on Optical Determination of Stress and Some 

 Applications to Engineering Problems. Dr. T. Rice Holmes, 

 Three Lectures on .Ancient Britain. Professor A. W. 

 Bickerton. Two Lectures on the New .Astronomy. Professor 

 .A. M. Worthington. Two Experimentally Illustrated Lectures 

 on The Phenomena of Splashes. Mr. M. H. Spielmaun. Two 

 Lectures on The Portraiture of Shakespeare. Mr. F. .A. 

 Dixey, Two Lectures on Dimorphism in Butterflies: 1. 

 Seasonal Dimorphism ; 2. Se.xual Dimorphism. The Rev. 

 John Roscoe, Two Lectures on The Banyoro: A Pastoral 

 People of Uganda ; 1. The Milk Customs ; 2. Birth and 

 Death Customs. Sir Alexander C. M.ackenzie. Three Lectures 

 on: 1. The Russian Music of To-day, with the kind assist.ancc 

 of the Hans Wessely Ou.artet : 2 and i. I'ranz Liszt (Cen- 

 tenary) (with Musical Illustrations). Professor Sir J. J. 

 Thomson, Professor of Natural Philosophy, R.I., Six Lectures 

 on Molecular Physics. The Friday l-'vening Meetings will 

 commence on January 19th, when Professor Sir James Dewar 

 will deliver a Discourse on He;it Problems. Succeeding 

 Discourses will probably bo given by Professor Bertram 

 Hopkinson, Dr. J. Mackenzie Davidson. Dr. J. .A. Harker. 

 Rt. Hon. Sir John H. A. MacDon.ald, Mr.G. K. B. Elphinst.me. 

 Dr. W. J. S. Lockyer, Mr. I'. Soddy, Professor DArcy W. 

 Thompson, Professor Sir J. J. Thomson, and other gentlemou. 



