35^ 



NA TURE 



\Feb. 14, I i 



sary to admit so great an elevation of the reflecting matter above 

 the earth, and thus removes a serious difficulty in explaining the 

 glow by known causes. 



In no case here has the sun during the day or at setting 

 appeared green. On December 28 and January 13 Venus has 

 appeared a beautiful green through the complementary crimson. 

 This fact becime important only when it was discovered that the 

 gc-een remainjd after the crimion had disappeared. The light 

 of th? plaiet Wis struggling through some medium invisible to 

 the eye, but which arrested the other colour,--. 



Aujther important pjint. The glow has been seen without 

 the slij;hte-;t trace of cirrus clouds behind it. Three times faint 

 ribbon-like stripes of cirri appeared in the first glow, but in the 

 second the gorgeous crimson hasgenerally been projected against 

 the clear blue sky. 



The writer has seen no notice of observations on the appear- 

 ance of the sun and sky during the day, and especially the 

 afternoon, before the brilliant sunsets. 



The peculiar appearance of the atmosphere in the vicinity of 

 the sun attracted his attention on the day the first remarkable 

 sun glow occurred. The sky was perfectly clear except around 

 the sun, which was embelded in a soft haze that extended out 

 some 6- or 8" on every side. Vet a distant boundary could not 

 be assigned to the haze, so gradually did it shade into the blue 

 of the sky. The sun was obscured so that the eye could look at 

 it for a moment and outline its disk. Covering the sun with the 

 hand the hize adjacent glowed like a furnace, the light 

 diminishing rapidly as the eye swept outwards. 



Two or three remarks, naturally spring from this appearance. 

 I. The haz; was not an ordinary cirrus clourl. It had no dis- 

 tinct bounding surfaces ; it was invisible everywhere except near 

 the sun. 2. There was, of c:)urse, no more of the matter form- 

 ing the haze arjund the sun than elsewhere. 3. It was capable 

 of reflecting intensely the light that fell upon it at a large inci- 

 dent angle, nearly go''. 4. The reflection of light in a high 

 degree by any substan.;e at a large incidence would indicate a 

 liquid. But the clearness of the sky showed the absence of con- 

 densed vapour. And yet there was something in the air around 

 the sun — and no more there than anywhere else — which was 

 then, some three hours farther east, flinging its gorgeous crimson 

 over earth and sky, and which, three hours later, would drape 

 the earth and sky of the observer in the same beautiful colours. 

 And what was that something ? Tliat is doubtless the great 

 question, and I can only echo. What was it ? If the answer be 

 "Vapour of water in sime peculiar state," then it is wondrous 

 strange that water, subject as it always has been to almost every 

 conceivable change in the air, should rarely if ever before have^ 

 assumed this peculiar state! Besides, the prevalence of this 

 pheno nenon around the globe, manifesting the same character- 

 istics everywhere, requires some marked and probably unusual 

 cause. 



As to the volcanic theory, it has some good points. It gives 

 an unusual explanation for an unusual occurrence. 



It might be expected that a convulsion which would ingulf 

 islands and mountains, and send the throbbings of ocean around 

 the globe, would leave .some tokens of its presence on the more 

 sensitive air. 



The difficulty of accounting for the suspension of solid particles 

 for months in air of extreme rarity m.ay be avoided by admitting 

 the effects to be due mainly to gases ejected in the eruptions. 

 Most of these being condensible by extreme cold would occupy 

 definite strata and not rise to an extreme height. 



The slaking of Krakatoa aad the admission of sea water to 

 the awful and fi-ry gulfs below, would, it seems, set free immense 

 quantities of chlorine from the salt water. As this gas is readily 

 absorbed by pure water it may have condensed around its mole 

 cules the vapour of the air, and thus become capable of reflecting 

 the light in a higher degree. 



Of course these are suppositions, consistent as far as we know 

 with luv ; and they may stand among other probabilities till 

 clearer light confirms or rejects them. 



In a coiimunication to Nature, December 13, p. 149, Prof. 

 C. Piazzi Smyth advances the idea that one of the conditions of 

 tlie red sunsets was the dryness of the lower atmosphere. The 

 hygrometric condition of the air here on the days the crimson 

 sunsets were seen, is given in the following table, taken from 

 the monthly reports of the writer to the U.S. Signal Office. 

 The two columns give the mean temperature of the dry and wet 

 'bulb thermometers (F.) for three observatio.is each day, at 7.32 

 a.m , 2.32 and 9.32 p.m. 



Dry bulb 



November 27 ... ... 29 ... ... 26'8 



December 5 ... ... 40 ... ... 38 



9 36'6 32 



■o 36 33 



25 29-5 26 



>> 28 ... ... 23-6 ... ... 22 '2 



January 13 37 33 



,> 17 23-2 21-2 



A mere inspection of the table shows that the dew point was 

 high, and the percentage of possible moisture in the air quite 

 large. Whether this weird and beautiful play of colours around 

 the dyin^ day is due to watery vapour in the air time will show ; 

 here it has cerlainly not been due to any dijuieiuy in ihe vapour 

 of the lower strata. O. N. S i odd.\rd 



Wooster, State of Ohio, United States, January 18 



Unconscious Bias in Walking 



The following little experiment seems lo show that if the 

 majority of people are, as Mr. Darwin argues, left-legged, they 

 would circle to the left in a mist, as Mr. Larden says they do. 

 I would call myself normal, my left leg being the stronger. 

 That is to say, like the majority, I jump from the left, rest my 

 weight standing on the left (a glance at a photograph album 

 shows this to be normal) and generally cross my right over my 

 left whilst sitting. Having put my-elf in a dark empty room, I 

 could not satisfy myself as to which way I circled, there not 

 being .space enough, but when I artificially lamed my.self by 

 putting a few tin tacks in my slipper, I circled strongly in the 

 direction of the sound foot. From what ha 1 been said in Nature 

 on the subject at the time, I expected the for-the-time-being 

 longer and stronger limb to circle round the other. The fact 

 seems to be that there is a bias towards ihe stronger, most-leant- 

 upon limb, irrespective of length. It is worlh'noting that, if the 

 object causing pain be placed under the inside of, say, the right 

 foot only, the experimenter will lean on the outside of that foot 

 and circle to the right. 



In the matter of left-leggedness I have requested reveral right- 

 handed people to feign lameness. Every one of them has limped 

 with the right foot ; and, on being asked to do so, has found 

 difficulty in imagining the left lame, and acting as if it were. 

 May it not be because the right leg is somewhat weaker that 

 canes are carried in the right hand ? 



But although left-leggedness qui strength seems normal, the 

 reverse seems to hold good qiid skill : one pushes a door to with 

 the right, feels his way down a dark slair w ith the right, kicks a 

 football with the right. A friend of mine, a skilful athlete, par- 

 ticularly known as a jumper, at first expressed astonishment that 

 there should be any doubt as to the left leg being the stronger. 

 On reflection he .added: "I'm not sure, however; figures in 

 skating are easier on the right." This nine figure-skaters out of 

 ten will assent to. It is to be expected, if my theory is correct. 

 The right leg is more easily controlled, guided, and kept in posi- 

 tion—in a word, the more skilful limb ; and at the same time 

 the left being the better kicker, the impulse is better given. 



It seems to me that mounting a horse from the near side is 

 not a mere fashion (except for the left-handed minnrity). The 

 stronger leg is put in the stirrup and gives the lift, whilst the 

 more skilful leg is thrown over the animal's back. 



It would be interesting to know which foot it is, if any in 

 particular, which Indian servants use for prehensile purposes ; 

 also whether the higher quadrumana are right or left hind-handed. 



I have noticed that persons walking in the street dwell longer 

 on the one foot than on the other, and I remember once arguing 

 that in-toed persons with a rolling gait were the only peiple who 

 VI ere not lame. I have been trying to observe this seriously for 

 some days, and believe it to be so, but as the mind natm-ally 

 invents a beginning and an end for a continuous motion it may 

 be imagination. \V. G. SiMPSON 



S, Randolph Cliff, Edinburgh, February 6 



The Ear a Barometer 

 The phenomenon described by my friend Mr. Boys, on p. 333, 

 is pathological, and not physiological. He is clearly suffering 

 from slight obstruction of the Eustachi.an tube, a canal which 

 leads from the inner side of the tympanic cavity into the posterior 

 fauces. Its natural relief is, as he very accurately describes, l>y 



