Sept. 1 3, 1884] 



NA TURE 



489 



and corresponding to the single mass on the nth. 6.53, seven 

 bands to south, a fine trio at an angle of 45°, five to north, much 

 less distinct. No sign now of counter-glow. 6.55, orange next 

 horizon ; bars to south as bright as the vertical mass. 6. 58, all 

 fading ; at no time reached beyond 25 altitude. 7. 1, only the 

 bases left of five bars to south, three vertical, and three to north. 

 Positions show well the place of the sun below the horizon. 

 7.3, rose tints quite gone ; none of last night's purple at all. 

 7.6, the cirro-stratus again tinged at edges. 7.9, as orange 

 fades, last vestige of bars goes ; stratus forming ; the cirro-stratus 

 still lit up. Sky very clear for York ; none of the hazy clouds 

 which accompanied the glows last season. 7.15, still red tinge 

 along horizon. 



September 14, morning, 5.7. — Find sky bright on waking ; rose 

 above, orange to greenish, yellow below ; orange most marked, 

 but rose wider spread, involving Venus, which, with Jupiter and 

 moon, showed complementary effect. Only one dark bar, low 

 down to north. Coloured area increased up to 5.15 ; fairly bright 

 at 5.20 ; perceptible at 5 25. Counter-glow very marked at 5-20, 

 massed above earth-shadow at anti-solar point, just where, yester- 

 day, there was no mddy tinge. No cirri about, only light scud 

 low down to east, from north to south. Very clear. 



This evening (14th) scud covered the sky a little before 7, and, 

 so far as I know, nothing special was observable. Is it possible 

 that the bars were due to shadows thrown by cirri below the 

 horizon? J. Edmund Clark 



Bootham, York, September 14 



The following observations of the warm, yellow circle about 

 the sun, unusual colours of sky and cloud, &c. , may interest 

 some of your readers just now. The beautiful, warm, yellow 

 solar halo, silvery white within, was seen on the following dates, 

 usually a little before, during, or after sunset : — May 18, 19, 24 ; 

 June II, 25, 26, 27; August 14., 19, 24, 27, 29; September 1, 

 3, 4, 5. On two occasions, in cloudless sky, the halo was visible 

 from noon to sunset. Unusual and beautiful colours were seen 

 near the sun on August 24, at 3 p.m., September I, 3, and 5. 

 The-e colours were first noticed at 2 p.m., November 26, 1S83. 

 The extraordinary sunsets began here in November 1883 ; the 

 dates are as follows : — 



1S83. — November 6, 14, 25, 2S ; December 1, 3, 4, 5, II, 15, 

 16, 17, 18, 19, 22. 



1884. — January 5, 11, 15; February 15, 24. 



The colours at sunrise were very fine on November 4, 29, and 

 December 4, 9, 19, 18S3 ; January 12 and February 9, 18S4. 



J. Gledhill 



Mr. Edward Crossley's Observatory, Bermerside, 

 Halifax, September 10 



Even last evening the glow was very marked. At 5.6 a belt 

 of orange-colour lay on the horizon near the point of sunset, 

 having a breadth of 4°. From this base shot up the bluish-white 

 cone, while on each side (south-west and north-west and skirting 

 the horizon) the sky had a smoky-brown aspect. The whole 

 was overtopped by an arch of a pale smoky-pink hue, the outer 

 circumference of which reached an altitude of about 30° as 

 measured from the horizon. At 5.8 the bluish-white cone had 

 become more intense, and the eastern sky was of a pale green. 

 At 5.12 the bluish-white cone, with brown sides and orange 

 base, was very distinct. At 5. 14 I noted a long ellipse of in- 

 tensely blue sky, the meridian forming its major diameter. On 

 each side, we-t and east, were areas of bluish-white, the latter 

 apparently being a reflection of the former, and having a base on 

 the eastern horizon of dull greenish-brown. At 5.21 I examined 

 the sunset sky with the spectroscope. The low sun-band was 

 becoming dark ; the merest possible vapour shading appeared, 

 detached, to the left of D, the little "c" lines were clear, and 

 B (dry gas) intense. At 5.31 the low sun-band had become 

 much deeper. By 5.38 a secondary glow had appeared: pale 

 lemon extended for some 7°, overtopped for the next 20° by an 

 intense smoky-pink, the opposite sky being a dull green, while 

 that immediately above the horizon south-west and north was 

 brown, and the landscape was tinted with a warm glow. The 

 little " a " band was now intense, so also was the low sun-band, 

 and all trace of vapour effects to the left of D had vanished. 

 At 5.43 the glow was " settling down " and had a total extension 

 of some 14 , 7° of orange and 7 of green. The whole thing 

 finished off with a belt of pale sea-green about io" in diameter 

 shortly after 6 o'clock. 



I have taken a great number of observations in re since my 

 arrival in Australia last December, and am now collating them 

 in accordance with the request of the Editor of Nature (vol. 

 xxix. p. 157). In a word, I am at present strongly in favour of 

 the volcanic hypothesis, and claim to have sufficiently shown in 

 a paper recently delivered before the Royal Society of South 

 Australia that the relatively high pressure prevailing over the 

 low pressure of Southern Asia at the time of the eruption pre- 

 vented the dust from reaching India, so as to produce the effects 

 of the "glow," until the lapse of a fortnight, and that the dust 

 travelled westwards and southwards aided by the rapid equatorial 

 rotation of the earth and the vertical distribution of pressure in 

 oceanic regions south of the Line. 



Clement L. Wragge 



Torrens Observatory, near Adelaide, July 31 



P.S. — I have repeatedly observed the "glow" in broad day- 

 light, and it is now (noon) visible as a bluish-white glare. — 

 C. L. W. 



Last year, when staying at this place, I was much struck by 

 the clearness of the air, the deep blue of the sky, and steadiness 

 of the stars. Moreover I used to notice on every clear day that 

 the highest cirri, when near the sun, exhibited very beautiful 

 spectrum colours. They did not behave as I have seen them 

 behave once or twice in England, viz. take up all the colours in 

 regular succession as their angular distance from the sun altered ; 

 but each cloud exhibited the colours in an apparently irregular 

 manner that reminded one of the appearance of mother-of-pearl. 

 This year it seems to me that the air is of a less deep blue, 

 and on every clear day there has been a very marked reddish 

 glow all round the sun. This red glow in the midst of what 

 would otherwise be a pure blue sky has been very noticeable. 

 It has nearly, though not quite, "swamped'' the diffraction 

 colours spoken of as so remarkable last year. W. Larden 



Avolla, Sion, Canton Valais, Switzerland (about 6500 feet) 



Pipe-Clay 



I was forcibly struck the other day by the analogy between 

 the beds of plastic clay (called here pipe-clay) which are every- 

 where met with interstratified with the different drifts of wash- 

 dirt, river-sand, &c. , in the tin-mines about this country, and 

 what was then to be seen in our own mine here. The mine had 

 been under water for about a month. On pumping the water 

 out, we discovered a layer of particularly fine, soft mud, four 

 inches in depth, of about the consistency of cream. It is evi- 

 dent that any animal or vegetable substance dropping into this 

 layer would sink through it and rest on the bottom. The 

 pipe-clay contains no fossils except portions of trees which rest 

 on the bed beneath it. Now, from the evidence before me 

 here, I am led to the conclusion that the beds of pipe-clay 

 were formed under like circumstances as these. The old 

 torrents which brought the drift down from the mountains were 

 undoubtedly continually changing their paths as they traversed 

 the valleys, being dammed by accumulations of timber and boul- 

 ders, thus causing the diversified and mixed-up appearance of 

 the beds, some of them containing huge trees and heavy stones : 

 these are the beds which contain the richest deposits of tin ores, 

 others being beds of fine quartz sand, with beds of materials 

 graduated between the two descriptions, and the beds of pipe- 

 clay interspersed. These last vary considerably in depth. I 

 have seen them all thicknesses between one inch and twenty 

 feet. 



The beds containing heavy materials were undoubtedly 

 brought down by tremendous torrents caused by heavy rain- 

 falls ; the lighter materials by the shrunken torrents during dry 

 seasons, or from a diversion of the course of the main stream. 

 If this is the case — and it seems to me most probable — I think 

 that it is a fair deduction to say that the pipe-clay was deposited 

 in ponds left by the decreasing torrents in their periodically-used 

 channels, which ponds would probably be perfectly still water, 

 and favourable for such a deposit, in the same way as this mine 

 was in a position favourable for the deposit of four inches of 

 slimy mud in a month. I am at a loss to account for the fact 

 that these beds (of finer materials) do not contain any animal 

 remains. The heavy beds contain very much heavy timber, but 

 of course all smaller and more delicate animal or vegetable 

 remains would be smashed up here : this does not, however, 

 apply to the other beds, if my theory is correct, and yet no 



