452 



KNOWLEDGE. 



November, 1910. 



METEOROLOGY. 



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



Thk weather of the week ended September 17th was fair and 

 dry, thou,sjh there was a thunderstorm in London on the 14th, 

 with heavy rain in many places. Temperature was below the 

 average, and ranged from 69' at Stonyhurst to 30° at West 

 Linton. On the .grass readings as low as 28° were reported. 



Rainfall was more than twice the average in England, E., 

 but was light in all other parts. At many stations in the 

 West the week was rainless. In spite of the low rainfall 

 sunshine was also deficient, e.xcept in Scotland and in 

 Ireland N. Douglas reported the largest ag.gregate. 50'S 

 hours (56%). and Birmingham the least 1'? hours (2%). 

 Glas.gow had more sunshine I37'6 hours. 42"., I than Guernsev 

 I23'3 hours. 26%). 



The teniperatiu'c of the sea round the coast \aried from 

 61° at Newquay, and about 60" on the Southern Coasts, to 52° 

 off the East of Scotland. 



The week ended September 24th. was fair and dry xery 

 generally, but cool. Temperature was below the average in 

 all Districts. The highest readings were 71° at Scarborough, 

 and 70" at Raunds, on the 24th, but at no other station was 

 70° reached. In Ireland the highest reported was 65° at 

 .Armagh and at Killarnex'. Rainf.iU was \ery light, and the 

 South of England uas practically rainless. Sunshine was 

 more abundant than in the preceding week, but it was still 

 defective in Scotland, N. and in Ireland. .At Strathpeft'er. the 

 total was only 1 TO hours (13%), and at Gordon Castle 11*3 

 hours. On the other hand many stations in the South reported 

 r.J hours and upwards, Tottenham as much as 56"9 hours 

 (66'':j). The temperature of the sea water ranged from 61° at 

 Newquay and at Margate to 52° on the East Coast of Scotland. 

 Frost on the ground was reported at many stations, and at 

 Llangannnarch Wells, while the minimum in the screen was 

 27". the reading on the grass fell to 19°. 



The weather during the week ended October 1st w-as less 

 settled than that of tlie preceding fortnight. Rain fell on 

 several days in the N.W. and W., and thunderstorms were 

 experienced on the 1st in many parts. Temperature, how- 

 ever, was markedly higher, being above the average in all 

 districts. The highest readings w-ere 76° at Raunds on the 2tSth, 

 and 75° at Tottenham. The lowest mininuun was 34° at Markree 

 Castle. Sligo, on the 30th. Atonlyafew stations didtheminimum 

 on the grass fall below freezing point, the lowest being 27° at 

 Cockle Park. Morpeth. Rainfall was less than the average in 

 all districts, except Ireland. S., where both rainfall and rainy 

 days were more than usual. .At some stations in the South 

 no rain was reported, and at others the fall was only one-tenth 

 of the a\"erage. 



Sunshine exceeded the average in some parts, but was less 

 than tlie average in Ireland, Scotland, England, S.W,, and 

 English Channel. Cromer reported the highest aggregate, 

 46'0 hours (55%), while Falmouth had only 16'4 hours (20%). 

 Glasgow reported lO'l hours (12%^). 



The week ended October Sth opened with hea\y rain in the 

 Western and N.W. districts, and some more moderate falls 

 with thunderstorms elsewhere, but was afterwards fine and 

 warm. Temperature was above the average in all districts, 

 by as nntch as 6' in Scotland, E. The highest reading was 

 74° at Cromer on the 2nd. with 73° at Hillington and Raunds. 

 In Jersey the highest reported was 66°. and in Scilly only 63°. 

 The lowest reading obserxed was il° at West Linton on the 

 7th, the next lowest being 37° at Newton Rigg, near Penrith. 

 On the grass the lowest reading reported was 29°. Rainfall was 

 below the average in all districts, especially so in the East and 

 .South of England. .At Yarmouth, Felixstowe and Clacton no rain 

 fell, and at a large number of places there was rain on only 

 one day. Sunshine was in excess generally. The highest 

 aggregate was 46'2 hou-s (5S%) at Guernsey, the lowest 6 6 

 hours (8%) at Castlebpy, Birmingham reported 15'5 hours 

 (.19%), while Glasgow had 230 hours (29%). The temperature 



of the sea water varied from 61' at Margate and Seafield to 

 51" on the N.E. of Scotland. .Aurora was observed in 

 Aberdeen on October 6th and Sth. 



During a kite ascent at Pyrton Hill on (October 4th, a 

 remarkable current of dry air was observed. On the ground 

 the humidity was 90% (saturation = 100). at 300 feet no 

 change was observed, but at 1,600 feet the humidity had 

 increased to 95%. At 3,300 feet, however, the percentage 

 was only- 40%, at which it remained till the kite reached its 

 greatest height. 4.400 feet. 



Pyrton Hill at the time was on the Northern side of a large 

 anti-cyclone, which had its centre over the Bay of Biscay. 

 On the ground the wind was from W. by N., but as the kite rose 

 the direction veered to N.W., and the force increased to 

 10m. per second. A few clouds were met with at about 

 2,300 feet, and from 2,500 feet the temperatiu-e increased with 

 height instead of falling. 



LECTURES ON MlCTi:) >ROLOGV.— Announcement is 

 made by the University of London that Dr. W. N. Shaw, 

 F.R.S., Reader in Meteorology and Director of the 

 Meteorological Office, will deliv er two lectures on '" Modern 

 Meteorology, Dynamical and Statistical." at the new- 

 Meteorological Office in the Exhibition Road. South 

 Kensington, on Mondays, November 21st and 28th, 1910, 

 at 5 p.m. I No tickets required). 



.MICROSCOPY. 



By A. W. SHErPAKD, F.R.M.S., 

 icitli the assistance (if the foUoicing luicroscopists : — 



Ariiilk C. IUnkiki I) .\rthlk Kari am'. 



lAMts Bi RTON. Richard T. Ekwis, F. R.M.b. 



The Rev. E. W. Bowkui., M.A. Chas F. Rolsselet, F.R.M.S. 



Charles H. Cafkyn. D. |. ScotKhfEiD, FZ.S., F.R..M S. 



C. 1). Scar, F.K.J).S. 



AN INTERESTING LARVA (Sitniiliiiiii reptaiis).— 

 During a recent holiday, camping out on the banks of the 

 river Teme, near Tenbury, Worcestershire. I was much 

 interested in these larvae, which are common in that river, 

 or. at all events, in that locality. 



The larvae are only found in the most rapidly running 

 water on various water weeds — in this instance R. aqitatilis. 

 No mere words can give an idea of the vast numbers in which 

 they were found ; one could pull out a length of weed which, as 

 weed, was usually invisible on account of the wriggling 

 niass of larvae attached to it. Had one so desired, a bucket 

 could have been filled solid with them without difficulty. 



The larva itself is a curious little animal, when full grown 

 about 11-12 mm. long, of a greenish black colour, and, 

 although not so transparent as the bulk of aquatic larvae, 

 still permits its internal economy to be easily made out. Its 

 nervous system, in particular, is very distinct. 



From the nature of its environment of rapidly rushing 

 water, it is provided with most efficient devices for retaining 

 hold of its support, in the form of two suckers, one on the 

 thorax, the other at the extremity of the last segment of the 

 abdomen. These suckers are each furnished with many rows 

 of sharp claws, or hooks, to add to their efficiency. 



The larva appears to hang on to its support as a rule by 

 the abdominal sucker, using the other to crawl about the weed 

 in the same manner as a geometer larva. It normally holds 

 on with its body as near to a right angle to the weed as it can 

 get, waving the body to and fro in all directions in search of 

 food. Should it be accidentally dislodged, it has another 

 safeguard in its capacity for spinning a thread, and along 

 which it slowly crawls back to safety. The salivary glands 

 which furnish this thread are of enormous size, and form the 

 most prominent anatomical feature of the insect. 



The head is furnished with a powerful biting mouth of the 

 usual type, and, in addition, is provided with two pairs of very 



