jAMTAJiy 20, 1921] 



NATURE 



66d 



as Locke says : " Vague and insignificant forms of 

 speech and abuse of language have so long passed 

 for mysteries of science ; and hard and misapplied 

 words,' with little or no meaning, have, by prescrip- 

 tion, such a right to be mistaken for deep learning 

 and height of speculation, that it will not be easy 

 to persuade, either those who soeak or those who 

 hear them, that they are but the covers of ignorance 

 and Tiindrance of true knowledge." J. Innes. 



12 Edward's Road, Whitley Bay, 

 Northumberland, January 4. 



Stellar Development in Relation to Michelson's 

 Measurement of the Diameter of Betelgeux. 



About thirty-five years ago Sir Norman Lockyer 

 held that certain of the reddish stars are probably in 

 an early stage of development. It was given out 

 yesterday in Press dispatches from Chicago that 

 Prof. Michelson had announced to the .'Vmerican 

 Physical Society and the American Association for 

 the .Advancement of Science that the experiments 

 with the Mount Wilson 8-ft. reflector at Pasadena, 

 California, had enabled him successfully to measure 

 the diameter of aOrionis by interference methods, 

 and that the diameter is about 300,000,000 miles, or 

 approximately three hundred times that of our sun. 

 The volume of Betelgeux is therefore about 27,000,000 

 times that of the sun; so that, if concentric with 

 the sun, the surface of Betelgeux would extend about 

 to the orbit of Venus. 



Now Betelgeux is a single star, and the mass, 

 therefore, is not definitely known ; yet if the mass be 

 not immensely larger than that of the sun we shall 

 have to conclude that the density is slight. Hence 

 this red star is in an early stag* of development, 

 which confirms Lockyer's views first put forth about 

 1886. If we make the density equal to that of our 

 sun, Betelgeux could not fill the orbit of Venus with- 

 out giving the star 27,000,000 times the solar mass, 

 which is quife inadmissible. 



Dr. Elkin's Cape heliometer measures made the 

 parallax of Betelgeux 0-023' and of Sirius 0-37*, so 

 that Betelgeux is only sixteen times more remote 

 than Sirius; and if we neglect a slight difference in 

 magnitude, largely due to colour, we may conclude 

 that Betelgeux gives about 256 times the radiation 

 i>f Sirius, which is itself ten-thousandfold more 

 luminous than our sun. .Accordingly, Betelgeux gives 

 .Tbout 2,560,000 times the sun's light. Now with any 

 idmissiblc mass of Betelgeux this immense luminosity 

 indicates an early stage of development, correspond- 

 inC to the larRP absolute diameter found by Michelson. 



T.J. J. See. 



Naval Observatory, Mare Island, 

 California, Decemb<'r 30. 



Heredity and Variation. 

 In a brief criticism of Sir .\rthdall K.iil'a Itlttr to 

 Nature (November 25, p. 405) in which he sought to 

 attach new meanings to certain well-recognised bio- 

 logical terms, I pomted out (Natl'rb, December 2, 

 p. 440) that if his contention that all characters arc 

 both innate and acquired in exactly the same sense 

 ,intl <li'gree is true, then it would follow that all varia- 

 tions arc also of one type, while experimental bio- 

 logists arc universally agreed that this is not the case. 

 \t least two catogoriex of variations are postul.iti'<l, 

 whether they tjc called blastogcnic and somatogenic, 

 germinal and somatic, mutations and fluctuations, 

 genotypes and phrnolypf-s, innate and acquired, karyo- 

 ^."■netic and cytogenetic, or by any other terms which 

 > nntrast an inherited and n non-inherited departure 

 frrim the parental type. 



NO. 2673, VOL, 106] 



Vet Sir Archdall Reid's only attempt to answer my 

 criticism that the universally admitted existence of 

 two types of variations undermines his whole posi- 

 tion is the very weak one of quoting Darwin's tenta- 

 tive theory of pangenesis, , which no modern biologist 

 would consider seriously a"S an explanation of heredity, 

 variation, or anything else. He says (Nature, 

 January 6, p. 596): "If we believe with Darwin in 

 his theory of pangenesis that the parts of the child 

 are derived from the similar parts of the parent . . . 

 the distinction between variations and modifications 

 vanishes." But we do not believe anything- of the 

 kind. The advance of knowledge made any such 

 belief impossible a generation ago. Even Sir .Archdall 

 Reid himself admits this when he says later in the 

 same letter (p. 598) that "Darwin . . . went hope- 

 lessly wrong ... in his theory of pangenesis " ! 

 Why, then, did he quote it as a reply to my criticism? 



This is only one, but it appears to me to be the 

 most fundamental, of the many contradictions in 

 which Sir .Archdall Reid has landed himself in his 

 attempt to remodel the usage of well-established 

 terms to his own liking. R. Ruggles Gates. ' 



King's College, Strand, W.C.2, January ij. 



The Mild Weather. 



.A fcPELL of mild weather set in shortly before Christ- 

 mas and continued until the. second week of January, 

 It followed a sharp touch of frost, when the sheltered 

 thermometer at Greenwich registered 16° on Decem- 

 ber 13, and for two consecutive days, December 12 

 and 13, the temperature remained below the freezing 

 point, whilst for ten consecutive days the thermometer 

 did not rise to 40°. A few facts relative to the mild 

 spell may be of interest. 



Greenwich temperatures are used throughout ; they 

 refer to the civil day, commencing at midnight, and 

 naturally differ at times from the ordinary meteoro- 

 logical day readings ending at some hour between 

 7 and 9 a.m. The results used are absolutely com- 

 parable. 



The period dealt with is from December 21 to 

 January 10, twenty-one consecutive days. This period 

 for 1920-21 was warmer than any corresponding period 

 in the last eighty years — since 184 1. The mean maxi- 

 mum temperature, the mean minimum temperature, 

 and the mean temperature obtained from the mean 

 of maximum and minimum were all the highest. These 

 three readings for the 21-day period in 1920-21 are: 

 M-o", 43-4°, and 477° F. The next highest means, 

 for 1872T73, arc .i;i-2°, 428°, and 470°, followed by 

 1915-16 with 50-9°, 410°, and 46-4°, and by 1852-53 

 with 513°, 407°, and 460°. 



Dealing with the first ten. days of January this 

 year, they are the warmest on record for this perio*! 

 for eighty years, with the mean (mean maximum and 

 minimum) 47-8°, followed by 1873 and 1916 with 468°, 

 and by 1S53 with 460°. 



Considering the days with a temperature of 50° or 

 above for the 21 -day pcriwi, IVcembor ai to 

 January 10, there were 17 days in 1852- s.'?. '5 'n 

 1872-73, 14 in 1920-21, and 13 in 1876-77. The abso- 

 lute maximum temperature in the recent warm period 

 rose to 56° on three days, and in the past there has 

 been no temperature higher than 57°. 



The mild weather we h.ive just passed through had 

 ten nights with the minimum temperature n\ 45° or 

 above, which is more than in any corresponding period 

 since 1841, and in all there were previously only two 

 periods with more than five such warm nights. 



The mean temperature for the twenty-one days to 

 January 10 thi>i v<'.ir i.s abo<it lo** warmer than the 

 normal. _ Ciias. Harding. 



65 HolmewcMwl G.Trdrn-. *^ W •. Jnnuarv 15. 



