March, 191J 



KNOWLEDGE. 



Ill 



iiepheline syenite, Lacroix describes two new minerals : 

 villiaiiiiiitc (sodium fluoride), of a violet or carmine-red tint, 

 supposed tetrogonal sj-mmetry, and soluble in water ; lositc. 

 a mineral allied to cancrinite, but differing from it in several 

 particulars, notably in lesser birefringence. 



.\s no associated strata are known, nothing can yet be 

 determined as to the geological age of this alkaline series. On 

 the adjacent mainland of French Guinea there occurs a totally 

 different series of rocks, consisting of hypersthene granite 

 (charnockite), norite, gabbro, and peridotite, a series which 

 has much in common with the charnockite rocks of India. 



CRYST.-\LLIZED TURQUOISE.— Hitherto the turquoise 

 has never been found in distinct crystals. It has always been 

 opaque and massive, usually of a green colour, only the best 

 qualities shewing the well-known blue. It is found in irregular 

 masses filling up cavities and fissures in the mother rock. .An 

 occurrence from Virginia (Schaller, Aiiicr. Joiirit. Science, 

 January, 191 2t, however, seems to show that turquoise may 

 sometimes assume a definite crystallized form. The specimen 

 consists ot irregular fragments of glassy ijuartz cemented by 

 thin layers of turquoise crystals. On each side of the 

 specimen is a drusy. botryoidal layer, bristling with minute 

 crvstals of a bright blue colour. Their density is 2-84. 

 and whilst their smalliiess rendered their crystallographic 

 determination difficult, it is believed that they have triclinic 

 symnietrv and are isomorphous with chalcosiderite. A chemical 

 analysis gives the following result : — 



P.O, 34-13 



.\i,0:, 36-50 



Ke,0:, -21 



CuO 9-00 



H,0 20-\Z 



99 • 96 



The fornmla derived from the ratios of the analysis is 

 CuO, 3 .-M-O;,. 2 FaOo, 9 H.>0. The above analysis agrees 

 very closely with one by Penfield on very pure massive 

 material from Nevada. The correct formula for chalco- 

 siderite is similar to the above, with the substitution of iron 

 for aluminium. Moreover, its crystal-angles are \ery close to 

 those tentatively given for the minute crystals of tunjuoise. 

 Consequently there is a strong probability that the two 

 minerals are isomorphous. 



METEOROLOGY. 



By John A. Curtis. F.R.Met.Soc. 



The weather of the week ended January 20th. as set out in the 

 statistical tables issued by the Meteorological Office in the 

 Weekly Weather Report, was wet and unsettled. Snow or 

 sleet was general during the earlier days of the week, and the 

 falls were heavy except in the Southern parts of the country. 

 Temperature was above the average in Scotland, N., the 

 southern parts of England and in Ireland, but below it else- 

 where. The \ariations, however, were nowhere \ery large. 

 The highest of the maxima was 57" at Fort Augustus, on the 

 17th. In Jersey the highest reading was 52°. Readings of 

 50 or upwards were reported in all districts except England, 

 N.E. and E..and Scotland, W. The lowest reading reported was 

 18' at Balmoral on the 20th. but temperatures down to 22' were 

 recorded at several other stations. In Ireland, however, the 

 temperature did not fall below the freezing-point, and in the 

 English Channel the minimum was 35". The lowest reading 

 on the grass was 15 at Balmoral. 



Rainfall was in excess of the average in all districts except 

 Scotland. N. and Ireland, N. The wettest district, relatively, 

 was the Midland Counties, where the recorded fall was nearly 

 four times as much as usual. .At Birmingham the total fall 

 was more than five times the average. 2-22 ins., as compared 

 with the average of 0-44 in.' Sunshine was in defect in all 

 districts, and at every individual station except two, Markree 

 Castle and Scilly. The last-named station was the sunniest 

 in the British Islands with a mean daily duration of 2-0 hours 



or 24%. At Westminster the week was sunless. The 

 temperature of the se.a water round the coasts varied from 

 37° at Scarborough to 50° at Scilly and Salcombe. 



The week ended January 27th was dull and r.ainy in the 

 southern districts, but mostly fair elsewhere, but with much 

 mist or fog at many English stations. 



Temperature was below thie average in all districts except 

 the English Channel, and in many parts the deficiency was 

 considerable. The highest readings of the week were 55 at 

 Bettws-y-coed and 53 at Killarney. In the English Channel 

 the maximum was 52', but in most of the districts the maxima 

 failed to reach 50 . The lowest readings were 18' at Balmor.al 

 and 21" at Poltalloch. In the English Channel the minimum 

 was 39 , but in every other district sharp frost was reported. 

 On the grass the lowest readings recorded were 15 at Balmoral 

 and Hillington. and 17 at Newton Rigg, Llangauimarch and 

 Markree. 



Rainfall was above the average in England, N.E., E. and 

 S.E., the Midlands and the English Channel, but was in 

 defect elsewhere. The defect in many cases was extreme, 

 and at some stations the week was rainless. In Ireland, N. 

 the mean for the week was only 0-01 inch as compared with an 

 average of 0- 81 in.. and in Scotland, N. the mean was 0-11 in., 

 the average being 1 • 63 inches. 



Sunshine as a rule was in excess in those districts where 

 rainfall was i!\ defect. The sunniest district was Ireland, S., 

 with a mean daily amount of 2-3 hours (28%). Scotland, N., 

 with a mean of 1 -8 hours, was 12 % in excess of the average, 

 while the English Channel, with a daily mean of 1-9 hours, 

 was 4 % below. At Westminster, the daily mean was only 

 0-2hours (2%t. Themean temperature of the sea waterranged 

 from 40-0 at Burnmouth and Cromarty to 48-4 at Scilly. 



The week ended February 3rd was very cold, but dry and 

 sunny. Temperature was below the average in all parts, the 

 deficiency aminmling to as much as 10°- 1 in the Midland 

 Counties, and to 9-7 in England, S.W. The highest of the 

 maxima was 49' at Waterford, but at many of the stations in 

 the Midlands and England. E., the maximum for the week 

 was under 40°. In the English Channel 47^ was the highest 

 reading recorded, at Guernsey, on January 30th. The mininia 

 were 15° or below in every district except the English Channel 

 where the lowest reading was 28°. The lowest readings were 

 4" at Balmoral on the 2nd, 9 ' at Llangammarch and 10° at 

 Fort .Augustus. On the grass readings down to zero were 

 recorded at Norwich, Balmoral and at Burnley. 



Rainfall was light very generally, and was below the average 

 in all districts. Indeed, over a large part of the country the 

 week was practically rainless ; thus, in England, S.W. the mean 

 total for the district was 0-01 inch, the average being 0-82 

 inch. Bright sunshine, on the other hand, was above the 

 normal everywhere, the excess reaching 30% in the English 

 Channel, where the mean daily duration was 5-2 hours or 

 57% of its possible duration. The advantage of the suburbs 

 as regards duration of sunshine is strikingly illustrated by the 

 figures for this week, the mean daily duration being at 

 VVestminster 0-5 hours (6%); at Camden Square 2-6 hours 

 (29%l, but at Hampstead 3-7 hours (42%). 



The mean temperature of the sea water varied from 

 37°-9 at Scarborough to 47°-8 at Plymouth. 



The week ended February 10th was at first \er\' cold, with 

 snow showers in nearly all parts. .After Monday, however, a 

 thaw extended over the country from the southward, the air 

 became humid, and rain was frequently experienced. Tem- 

 perature for the week was below the average in all districts 

 except the English Channel, where it was very slightly above. 

 Maxima above 50 were reported from all districts, the highest 

 readings being 56" at Bath, Clifton and Llandudno. The 

 lowest readings were on the Sunday or Monday, and were 

 below 17 in all districts except the English Channel, where 

 the minimum was 27". The lowest reading reported was — 5t 

 at West Linton, on the 4th, or 37" below freezing-point. At 

 Balmoral a reading of —Z' was recorded on the 5th, and a 

 Gordon Castle the minimum was 1" on the 4th. On the grass 

 a reading of —7 was recorded at Crathes. 



Rainfall, though but little more than one third the average 

 amount in Scotland, N., was in excess in Scotland, W., and in 



