August, 1912. 



KNOWLEDGE. 



Rainfall was in excess in all districts except the English 

 Channel, where it was only half as much as usual. In many 

 parts of the Kingdom, however, it was more th.an double, and 

 in England, N.E., it was nearly three times the average. At 

 .Mnwick Castle the total for the week was 2-36 inches or more 

 than five times the average amount, 0-44 inch. 



Sunshine was above the average in England, E., S.E., the 

 Midland Counties and in Ireland. S., but below it elsewhere. 

 The variations were somewhat remarkable, England, E., 

 having the largest daily average. S-2 hours 150%) and 

 Scotland, E.. the smallest daily average, 1-3 hours (7%). In 

 the one case the daily value 

 was 1 • 7 hours above the 

 average; in the other case 

 it was 4-6 hours below it. 



The mean temperature of 

 the sea water varied from 

 48° -2 at Berwick to 59°- 7 

 at Margate and Seafield. 



The weather of the week 

 ended June 22nd continued 

 very unsettled in the West 

 and North, with frequent 

 heavy falls of rain. Over 

 the south-eastern counties, 

 however, the weather im- 

 proved after the 17th. 

 Thunderstorms were re- 

 ported on the 16th, 19th, 

 and 22nd. 



Temperature was above 

 the average in the greater 

 part of Engl.and and in 

 the English Channel, but 

 was below it in Scotland 

 and Ireland. The excess 

 was greatest in England, 

 E., where the district value 

 was 60° -3 as compared 

 with the average of 57°- 8. 

 Some very high tempera- 

 tures were recorded during 

 the week, the highest being 

 84° at Greenwich, 83" at 

 Hampstead and Camden 

 Square and 82° at Tun- 

 bridge Wells. The lowest of the minima were 35° 

 at Balmoral and 37° at West Linton, PoltoUoch and 

 Kilmarnock. Ground frost was reported at Crathes (29°), 

 Newton Rigg (30°) and Balmoral and Glasgow (32°). 



The temperature of the soil at one foot depth was above 

 the average at most of the English stations, but below it in 

 Scotland and Ireland. .\t a depth of four feet it was very 

 close to the normal. 



Rainfall was in excess except in England, E., S.E., the Mid- 

 lands and the English Channel. In Scotland, W.. and in 

 Ireland the total precipitation was about three times as much 

 as usual ; in England, S.E., and the English Channel it was 

 less than one-third the average. 



Bright sunshine was in defect except in England, E. and 

 S.E. The district values varied from 8-5 hours (51%) in 

 England, E., to 2-5 hours (15%) in Ireland, S. The sunniest 

 stations were Greenwich with a daily average of 9-2 hours 

 (56%) and Southend 9'1 hours (55%), while at Balruddery 

 near Dundee the value was only 1-9 hours (11%). ."^t West- 

 minster the average daily duration was S-3 hours (51%). The 

 mean temperature of the sea water ranged from 49° -4 at 

 Lerwick to 61° -9 at Margate. 



The weather of the week ended June 29th was generally 

 cool and unsettled, with much rain and many thunderstorms. 

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

 England, N.E. and E., but below it in all other districts except 

 Scotland, E., where it was normal. The extremes recorded, 

 however, were neither so high nor so low as in the preceding 

 week, the highest readngs recorded being 78" at Margate, 76° 

 at Greenwich, and 75° at Gordon Castle, Yarmouth, Geldeston, 



s:^ 



and Camden Square ; and the lowest 40° at Balmoral, and 

 41° at West Linton. No frost on the ground was reported, the 

 miniuunn on the grass being 34° at Crathes and at Hampstead. 

 The soil temperature at one foot depth was above the 

 average ; but at four feet depth the excess was small, and in 

 some parts of the country it was slightly in defect. 



Rainfall was in excess in all districts except Scotland. N., 

 where it was in defect. 



In England, S.W., and in Ireland, S., the totals were more 

 than three times as much as usual. At Arlington, N. Devon, 

 the amount collected during the week was 3-46 inches, as 

 compared with an average 

 of 0-78 inches. At West- 

 minster the total did not 

 quite reach half an inch. 

 Sunshine was in defect 

 very generally, but in Eng- 

 land, S.E., and the English 

 Channel it was slightly 

 above the average. The 

 sunniest district was the 

 English Channel with a 

 daily average of 8-8 hours 

 (55%), while in Scotland, 

 N., and Ireland, N., the 

 mean daily value was only 

 3-9 hours (23%). The 

 sunniest stations were 

 Guernsey, 10- 2 hours (64%), 

 and Weymouth 9-2 hours 

 (57%). 



The temperature of the 

 sea water round the coasts 

 ranged from 50° at Lerwick 

 and Berwick, to 63° at 

 Margate and Teelin, and 

 66° at Seafield. 



MICROSCOPY. 



By F.R.M.S. 



HARVEST - MITES.— 

 The hot dry days of last 

 summer were particularly 

 favourable to these minute 

 pests, and holiday- 

 makers in many districts must have suffered from their 

 attacks, probably without ever catching sight of their 

 tormentors. Harvesters or harvest-bugs are a species of 

 grass-mite ; they are bright red in colour, and the body alone 

 is about one seventy- fifth of an inch long. The photomicro- 

 graph shows the six-legged stage magnified one hundred and 

 fifty times. It will be seen that it has rather a formidable- 

 looking beak, and that its legs, which are about as long as its 

 body, are each armed with three claws. The mites are 

 difficult to detect on the human skin, but can be easily seen 

 on a sheet of white paper ; specimens can be obtained by 

 putting a sheet of paper under long grass and beating the 

 grass with a stick. The harvesters will be seen as quickly- 

 moving red specks, and can be caught on the tip of a fine 

 camel's hair brush previously moisted with water or spirit. 

 Ernest Marriage, F.R.P.S. 



LOW POWER PHOTOMICROGRAPHY— LIGHTING 

 AND BACKGROUNDS.— In photomicrography generally, and 

 perhaps especially in the domain of low power work as used 

 by naturalists, I would be inclined to say that success, like a 

 three-legged stool, depends on three supports, viz., (1) focus- 

 ing, (2) lighting (including backgrounds), (3) exposure and 

 development. 



In this note I propose, as briefly as may be, to offer a few 

 general suggestions on the topic of lighting and backgrounds, 

 for the benefit ot the busy worker who wants to get at the 

 heart of the matter as directly as possible in its practical 

 application, and without going through the mill of trial and 

 error. At the same time, be it said, to anyone disposed to 



Figure 351. 

 The six-legged stage of a Harvest Mite X 150 diameters. 



