October 21, 1909 J 



NA rUKE 



48; 



is to "strike them with fasting spittle," i.e. to apply 

 saliva when rising in the morning, before any food has 

 been taken. G. Harold Drew. 



Marine Biological Laboratory, Plymouth. 



Orthite in North Wales. 



In March, 1908, an unfamiliar mineral 



vas discovered 

 by Mr. W. G. Fearnsides in a narrow vein which traverses 



the intrusive granophyric mass of Tan-y-grisiau, near 

 Ffestiniog, and was submitted to me for identification. 



It has proved to be the somewhat rare silicate orthite, 

 and its occurrence will be of considerable interest to 

 mineralogists both on account of the amount of material 

 available and for the large size of the crystals, which range 

 up to lA inches in greatest dimension. 



Hitherto orthite, which coVitains a number of the rarer 

 elements, such as cerium, lanthanum, didymium, yttrium, 

 &c., has not been found in any quantity in Britain, and 

 then onlv as microscopic crystals and grains. The crystals 

 from Tan-v-grisiau are well-formed, black to dark grey, 

 submetallic tables with bright faces ; they are conspicuously 

 tabular, parallel to the form TJioo;, and are modified by 

 narrow prism and dome faces. 



It is the " unknown and very interesting mineral " to 

 which the attention of those members of the Geologists' 

 Association who took part in the long excursion to North 

 \A'aIes this year was directed. 



The exact locality is the north-west face of a quarry at 

 Cefn-bvchan, south of Tan-y-grisiau, Blaenau-Ffestiniog, 

 belonging to the Ffestiniog Granite Quarries Co., Ltd. 



The phvsical properties of the orthite are undergoing 

 investigation, the results of which will be published at a 

 later date. Herbert H. Thomas. 



Geological Survey and Museum, Jermyn Street, S.W. 



Drought in South-west Ireland. 



Whilst all round us have been reports of wintry 

 weather and unceasing rain during the summer months, we 

 in this small south-westerly area of Ireland have been 

 passing through a period of abnormal drought, in fact a 

 record season, accompanied by high temperature through- 

 out. 



I have recorded the annual rainfall here (Bandon) lor 

 some years, but I have never had anything approaching a 

 similar experience, and the oldest inhabitant here cannot 

 recall so continued an absence of rain as we have felt 

 this season, that too in a country where the rainfall is 

 generallv excessive. I am bound to say, however, that 

 the elements are now distinctly making up for lost time, 

 as though in revenge for letting us off so easily before. 



I give vou the rain-gauge readings for the months June, 

 July, August, and September, which speak for themselves, 

 and may perhaps prove of some interest to your readers. 



The readings were taken with a 5-inch Negretti and 

 Zambra gauge, and registered daily : — 



/»)!(?.— Total for month, i-oS inches. Twenty-five days 

 absolute drought. Highest reading = o-47 inch, on June 24. 



July. — Total for month, 1-02 inches. Twenty-three days 

 absolute drought. Highest reading = 034 inch, on July 10. 



August. — Total for month, 0-54 inch. Twenty-five days 

 absolute drought. Highest reading = o-32 inch, on 

 August I. 



Sefitcmbcr. — ^Total for month 

 absolute drought. Highest 

 September 28. 



skv was clear over a large extent of England, and hundreds 

 of'persons saw the meteor, though only a small proportion 

 of that number have reported their observations. 



The great daylight meteor of 1900 January 9 was 

 directed from Aquila, that of 1894 February 8 emanated 

 from Hercules. It is seldom that meteors appearing at 

 such times can be suitably observed, as the sky does not 

 afford any reference objects such as is furnished by the 

 stars at night. VV. F. Denni.ng. 



An Aurora Display on October 18. 



I WITNESSED last night one of the finest displays of the 

 aurora borealis which it has been my good fortune to see 

 in this country. It happened at about 9 p.m., and I 

 was at the time upon one of the highest summits of the 

 Cotteswold Hills, close upon 1000 feet above the sea-level, 

 so that I had an uninterrupted view of the magnificent 

 spectacle. The first I saw of it was several streamers 

 and an indistinct band low down on the northern horizon, 

 with a detached red, cloud-like portion almost due west. 

 These resolved themselves eventually into two bands, the 

 uppermost stretching right across the sky from north-west 

 to north-east, and during the maximum phase of the 

 phenomenon was a truly grand spectacle, with numerous 

 streamers connecting the two bands. The uppermost band 

 finally faded away, leaving the lowermost one still visible 

 but very indistinct, with two or three faint streamers 

 shooting upwards. 



I take this opportunity of inquiring what is the most 

 austral or equatorial limit from whence the aurora borealis 

 is visible, or rather has ever been observed? This subject 

 is of particular interest to me from the circumstance that 

 when I was at Darjeeling some years ago I was informed 

 that the phenomenon had been seen from thence, although 

 this well-known hill station is so far south as 27" north 

 latitude. Although it is not impossible for it to be seen 

 from the altitude of Darjeeling (which is 7500 feet above 

 the sea-level), for far away are seen the tops of the Hima- 

 layas, I feel convinced that what has been seen from thence, 

 and mistaken for the aurora, is nothing more than the after- 

 glow or reflection from the snow-fields and glaciers upon 

 exceedinglv thin masses of aqueous vapour, or rather 

 spicules of snow, floating upwards to 1000 feet or more 

 above the summits of the highest Himalayan peaks. This 

 latter phenomenon I frequently witnessed after sunset, and 

 It certainly possessed the appearance, upon many occasions, 

 of the aurora, hence the mistake, possibly, of unscientific 

 observers. W. Harcourt-Bath. 



October 19. 



0-41 inch. Eighteen days 



reading = oo8 inch, on 



Geo. a. Armstrong. 



Ardnacarrig, Bandon, Co. Cork, October 13. 



\ 



The Meteor in Sunshine, October 6. 



The great daylight meteor of October 6 was observed 

 by many persons in various parts of the country. The 

 particulars to hand are not, however, very definite, and 

 it is scarcely possible to compute the real path of the 

 object. From a comparison of about fifteen descriptions, 

 there seems little doubt that the meteor moved in a direc- 

 tion from south to north over Reading, Thame, and on to 

 a termination near Market Harborough. 



The radiant point was in Leo, and it is hoped that more 

 observations of an exact character will be supplied. The 



2086, VOL. 81] 



NO. 



Jupiter's South Tropical Dark Area. 



All the transit estimates, numbering fifty-two, of the 

 south tropical dark area on Jupiter, obtained during the 

 apparition of 1908-9, have been reduced to longitude. The 

 area in 1908 December was found to be more than 50° 

 in length at the south equatorial belt. From this date to 

 the close of the observations in 1909 June its dimensions 

 exhibited a gradual increase, and in the latter month it 

 covered considerably more than 90° of longitude.^ This 

 longitudinal growth was due chiefly to a marked difference 

 in the observed rate of velocity of the two ends of the 

 area. While the preceding end drifted at a pretty norrnal 

 rate of 15° per month in excess of the adopted zero meridian 

 of System IL, the following end exhibited a monthly drift 

 of only 9°. The following part of the area, therefore, was 

 not keeping pace with the preceding portion, and accord- 

 ingly the object itself became distended in longitude. 



The mean rotation period of each end, as well as the 

 middle, of the area would seem to have been as under : — 



Mean rotation 



period 

 h. m. s. 



9 55 20 8 



Number of 

 observations 



Number of 

 rotations 



M»an daily 

 drift 



20 

 16 

 16 



430 

 295 



379 



-0-4823 

 -0'37';4 

 - 0-2989 



9 55 2V3 

 9 55 28-3 



The above period for the following end is the longest that 

 has been recorded, either for this or any other part of the 

 area, the existence of which became known in 1901 February. 



Leeds, October 15. Scriven Bolton. 



