February 15, 1912] 



NATURE 



0'/ 



froze instantly on touching a solid object. In driving 

 through Richmond Park 1 noticed the branches bending 

 under a weight of clear ice, and, what was even more 

 remarkable, the windows of my cab becoming thickened 

 by a layer of ice while the temperature was just at the 

 freezing point. Rain had been falling continuously until 

 the afternoon, when the drops began to solidify on con- 

 tact. From roofs and gates long icicles were formed, 

 increasing in size ; the grass was sheeted with ice, although 

 the ground had not been chilled by frost. 



It is not easy to explain the passage of very cold drops 

 through a warm layer of air without their temperature 

 being raised nearly to that of the layer, but, since the 

 objects on which they fell must have been above or about 

 the freezing point, the drops must have brought with them 

 a degree of cold sufficient not only to cause instant solidifi- 

 cation, but to retain the solid state some time after fall- 

 ing and to refrigerate the„o|^j[ects. The size of the drops 

 was not unusual. ' Rollo Russell. 



Prof. Meldola in his letter (Nature, February i, 

 p. 447; nl. rs to a similar occurrence to that described by 

 me in Nature of January 25, and he says, " it must, I 

 think, have been in 1866 or 1867." Prof. Meldola adds 

 that there must be many Londoners now living who can 

 remember the occasion. 



I well remember the occurrence, and my brother, Mr. 

 J. S. Harding, skated round Belgrave Square and the 

 immediate neighbourhood for two or three hours. 



May I give the following extract from mv Meteorological 

 Register, kept in the neighbourhood of Belgravia. which 

 shows the time and nature of occurrence? 



" 1867, January 22. — Slight rain from 7.20 p.m. to 

 10 p.m., half congealed before it reached the ground, and 

 forming almost simultaneously with its fall a sheet of ice 

 upon the earth, evidently the result of rain falling from a 

 stratum of warm air at no great distance from the earth, 

 and not having sufficient time to be converted from rain 

 before reaching us." 



This was the close of an exceptionally severe frost ; my 

 screen temperature on January 5 was '6-5°, the lowest I 

 have observed, and the Greenwich reading was 6-6°. 



I think some meteorologists would call the phenomenon 

 referred to by Prof. Meldola a silver thaw ; it is perhaps 

 somewhat different in character from a glazed frost, and 

 is a sure precursor of a thaw. Chas. Harding. 



The following note is to be found amongst the " Meteor- 

 ological Observations " at the end of " The Natural 

 History of Selborne " under the title of " Frozen Sleet," 

 and appears to be an example, and a remarkable one, of 

 the phenomenon of " glazed frost " : — 



"January 20. — Mr. H.'s man says that he caught this 

 day in a lane near Hackwood Park many rooks, which, 

 attempting to fly, fell from the trees with their wings 

 frozen together by the sleet, that froze as it fell. ThcMc 

 were, he affirms, many dozen so disabled. — White." 



Andrew \\'\tt. 



Scottish Meteorological Society, Edinburgh, 

 February 10. 



On Monday, February 5, I was in Bruges ; about 



8.15 p.m. I heard what I thought was hail beating upon 



the window panes. On leaving the house about fifteen 



minutes later I found that everything was covered with a 



film of ice at least a quarter of an inch thick. The 



phenomenon of " glazed frost " was very well marked, 



irticularly upon the iron railings which run along tin- 



le of the canals, and upon the twigs of the trees. The 



me cobbles with which the streets are paved were com- 



. "tely covered with smooth ice, and the roads were almost 



impassable ; I saw five people fall down in as many 



minutes. Franxis G. Belton. 



3.1'' Belgrave Road, Birmingham. 



Irn: letters of Mr. Harding (Nature, p. 414) and Prof. 

 M'ldola (Nature, p. 447) recall the following : — 

 On February 5, about 7.30 p.m., a heavy shower of 

 iin, which lasted for fifteen minutes or so, suddenly fell. 



NO. 2207, VOL. 88] 



Being caught in this shower, naturally I hurried but 

 qu.ckly found myself slipping rather than walking along 



JLrth tLr" "'^ '^f •■f'"d'-«P^ ^^^^ '" contact with tl?; 

 earth they apparently froze, the roadway quickly becom- 

 ing covered w th a coating of ice, which had a veVv^lazed 

 appearance. A stick which I had in my hand also bc^Jame 

 coated, and was quite glassy " to the touch. 



Although the shower was of so short a durai' 

 younger element of the people about at the tim. 

 themse ves sliding along the Promenade and down iiu- 

 mam street (which has a fair slope). 



The temperature during the day was about 32° F but 

 at the time of the shower it was about 33° F. 



r- . V /- ., , ,. ^- Wyndiiam Jeffreys. 



University College of Wales, Aberystwyth, 

 February 10. 



r hx 

 Ika. 

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Human Eyes Shining. 



With reference to the last paragraph in tli. In 

 Colon- 1 J. Herschel in Nature of January iS. 

 soniutuius seen human eves reflecting light in ih- wn 

 described, though, as indicated in the letters to Naturk 

 it IS difficult to get in the right position for seeing such 

 an occurrence. I have never tried a dark lantern The 

 best instance I have seen was in 1876, when I observed 

 the light from an oil lamp inside a little girl's eyes. It 

 was best seen when my head was between the lamp and 

 her, and when the shadow of mv head nearlv came upon 

 her eye. It appeared to be her retina that 'was illumin- 

 ated ; It was a bright orange-red, but varied in the amount 

 of red. When my eye was nearly in the same direction 

 as the lamp, the whole pupil was equally illuminated, but 

 when less nearly in \\m- same direction the side of the 

 pupil next my shadow was th,- brightest, or the onlv part 

 illuminated. The illumination was stronger when she 

 looked to one side of the lamp than when she looked at it. 

 Her sister exhibited the phenomenon less strongly, though 

 still brightly, but her father very slightly. In the external 

 appearance of these eyes there was nothing unusual. 



I have tried to see this phenomenon in my own eyes in 

 a looking-glass, with the sun as illuminator, but "could 

 only see a very faint illumination, very different from the 

 above-instanced cases. 



I have never used .in ophihalmoscope, but I understand 

 that whin an rvi i- s,, , l.^n \-. ,! ili,. light is red or orange. 



T. W. Backhouse. 



W's| Ilondon Ilousr, Suiulrrland, l"ebruarv u>. 



Chalk and Ice. 



I HAVE read with much interest the letter on " Chalk 

 and Ice " in Nature of February 8, as I had observed the 

 same phenomenon on January 7 of last year. 



There had been heavy rain all the previous day and a 

 sharp frost at night, when, in walking over Ballard Down 

 from Swanage to Studland. in the early morning, I 

 noticed lumps of chalk with tibrous masses of ico adhering. 

 till' ice in some cases being larger than the rlialk fr.ig- 

 imnt. 



i 111' soil consisted of sandy clay resting on lin- dip 

 slope of the chalk, and fragments of the latter wore very 

 numerous, each with its adherent ice, which, on account 

 of its prismatic structure, sparkled in the sunlight with 

 bright flashes of colour, the effect I>eing very beautiful. 



The formation of ic( below the surface, as suggested, is 

 interesting, as it would certainly be nn important factor 

 in the gravitation of soil on a chalk slope during rold 



pen 



W 



2S niointl' 



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Candlemas Day. 



Is .iddition to th^ provrbs about the weathor on the 

 .second of February quoted among the Notes in last 

 week's Naii'Ri;. allow me to give the following, which was 

 told to me by the late Dr. Corrie, .Master of jpsui roll#»gc, 

 Cambridge : — 



" Si sol splendetcat MaHa purificant' . 



Majus erit frigus post festam quam tun ante" 



O. Fisher. 



