November 24, 1923] 



NATURE 



759 



from another specimen. In this new photograph 



the great toe is large and diverges from the other 



toes as in my Fig. 2 (here printed). But its terminal 



phalanx is flexed and the foot is so posed that the 



s;reat digit projects over and in front of the bases 



>{ the other digits and is consequently foreshortened 



1 the photograph. The shape of the plantar surface 



nd that of the heel is not that shown in the photo- 



raph of Mr. Akeley's cast — but is that already 



I miliar to those who have made a study of the 



Drilla's foot. It is a happy circumstance that Mr. 



\keley presents his readers with conclusive evidence 



)ndemning his plaster cast of the gorilla's foot, 



(le by side with the photograph of that misleading 



roduction (which faces p. 242). He could not deal 



ore frankly and straightforwardly with the matter 



Jian this. E. Ray Lankester. 



October 5. 



Determination of the Temperature of the Upper 

 Atmosphere by Meteor Observations. 



In a letter published in Nature for February 10, 



>23 (p. 187), I referred to the possibility of deter- 



ining the temperature of the upper atmosphere on 



ny occasions when the disruption of a meteor has 



icn heard and the time interval between sight and 



)und has been recorded. I have now to report 



iiat I have only been able to learn of two instances 



which have looked favourable, and that neither of 



tliem has yielded useful information. 



The first case is that of the meteor of December 21, 

 1S76, which is described in the American Journal of 

 Science and Arts, Series III., Vol. 13, p. 166, 1877, 

 ;ind in a paper by Prof. C. U. Shepard, on p. 207 of 

 the same volume, as well as in a paper read by Prof. 

 D. Kirkwood before the American Philosophical 

 Society, March 1877. The meteor was under observa- 

 tion from Kansas to the shores of Lake Erie. 



Over the State of Missouri one or more explosions 

 occurred, and the disintegration continued until there 

 was " a large flock of brilliant balls chasing each 

 other across the sky." In some places " a terrific 

 series of explosions were heard." It is clear that 

 the identification of the source of any particular 

 sound is out of the question. The following tantalis- 

 ing observation quoted by Kirkwood is therefore of 

 no service: " Rev. James Garrison, who resides one 

 mile south of Bloomington, noticed by his clock the 

 time of the meteor's disappearance and also that of 

 the subsequent rumbling sound, together with the 

 violent jarring of his house. The interval was 

 15 minutes, indicating a distance of 185 mUes." 

 The implication that the speed of sound is a universal 

 constant is to be noted. 



The second case is that of the meteor of July 27, 



T894, ^ very detailed account of which is given by 



I'rof. E. S. Holden in "Meteors and Sunsets" 



' ontributions from the Lick Observatory, No. 5). 



: is clearly established that the meteor exploded 



I a height of about 28 miles and near to Merced, 



I alifornia. The determination of the time of passage 



of the sound to the Lick Observatory appears from 



the statements of the observers to be precise enough. 



live observers who noted the time at which the 



sound was heard agree within two or three seconds. 



For the time at which the explosion was seen there 



is, however, only one observation with any claim to 



precision . 



The time of explosion (A. F. 



Poole) .... 

 The time of hearing the 



report (five observers) . 

 Time of passage of sound . 



7h. 29m. 45S.±ios. 



7h. 36m. 14s. ± 3s. 

 6m. 293.^:138. 



The distance from the observatory to the point at 

 which the explosion occurred is estimated by Holden 

 as 59-3 miles — i.e. 95 km., due allowance being made 

 for the height of the observatory above sea-level. 



The data imply that the average speed of the 

 sound was 244±8 metres per second, and that the 

 average temperature of the air between 28 miles and 1 

 mile above sea-level was i48°±9° A. (about - 193° F.). 



In 1894 such an estimate was accepted without 

 difficulty. In 1923 it looks wrong. The most likely 

 place for a flaw is in Poole's observation. There is 

 no statement as to how it was made : if with an 

 ordinary watch an error of a whole minute is not 

 unlikely. With the appropriate amendment the 

 time of travel of the sound becomes 5m. 29s., the 

 speed 289 metres per second, and the temperature 

 207° A. 



Some confirmation is found in the only report 

 received by Prof. Holden in which a single observer 

 states the interval between sight and sound of the 

 explosion. Mr. George Bray saw the whole pheno- 

 menon at Santa Clara, and gave the interval as 

 j\ minutes. According to Holden's sketch-map, the 

 horizontal distance was 70 miles, the path of the 

 sound was therefore about 75 miles or 121 km., and 

 the speed 278 metres per second. This corresponds 

 with an average temperature 192° A. and is quite 

 plausible, but with the limitations implied by an 

 estimate of 7 J minutes, little weight can be attached 

 to the result. 



I have trespassed so far on your space because 

 I wish to emphasise the fact that any one who has 

 the good fortune to see a meteoric explosion will be 

 doing good service if he notes the time by his watch 

 (writing it down immediately) and listens for the 

 sound. If he is able to compare his watch with 

 a standard clock, so much the better, but from the 

 present point of view the interval is of greater 

 importance. 



In conclusion, I should like to thank Miss Williams, 

 assistant secretary of the Royal Astronomical 

 Society, who devoted much time to looking through 

 the literature of meteors on my behalf. 



F. J. W. Whipple. 



6 Addison Road, Bedford Park, W.4, 

 October 25. 



Experiments on Ciona Intestinalls. 



In the issue of Nature for November 3, p. 653, 

 there appears a letter from my old friend and former 

 colleague, Mr. H. M. Fox, in which he records an 

 attempt which he made this summer to repeat Dr. 

 Kammerer's experiments on Ciona. These experi- 

 ments consisted in inducing an abnormal growth of 

 the siphons of Ciona by repeated amputation. Mr. 

 Fox amputated the siphons of Ciona, but the length of 

 the regenerated siphons was normal. 



As Dr. Kammerer took a deep interest in the pro- 

 jected repetition of his experiments on Ciona, and 

 wrote to me twice this summer to learn if repetition 

 were being attempted and under what conditions, 

 perhaps you will allow me to make some remarks on 

 Mr. I--ox's letter, as Dr. Kammerer is now in America. 



l)r Kammerer, whilst in Cambridge, wrote out a 

 full account of the precautions to be observed in 

 making these experiments. At that time he did not 

 know that Mr. tox was going to take up the work : 

 another Cambridge biologist had undertaken to do so, 

 but this gentleman was prevented by illness from 

 doing the work. To him, however. Dr. Kammerer 

 had transmitted his information. I understand — 

 Mr. Fox will correct me if I am wrong — that Dr. 

 Kammerer's instructions did not reach Mr. Fox. 



NO. 2821. VOL. I 12] 



