March, 1915. 



KNOWLEDGE. 



83 



nick in the sky-line seen towards the right side of the photo- 

 graph. The collapse of the block of sandstone which for- 

 merly filled the arch took place along well-marked joint- 

 planes, seen on the right side of the arch. 



Figure 70, on page 80, shows caves formerly eroded by 

 the sea on the ten-foot raised beach platform of the 

 Holy Isle, opposite Lamlash. These are well above high- 

 water mark, and make a recess in the cliff which rises at 

 the back of the raised beach. 



In both photographs the sandstones show a remarkable 

 hollow weathering, frequently with raised ribs, forming a 

 reticulated pattern. This is supposed to be due to variations 

 in the quantity or composition of the abundant calcareous 

 cement of the Triassic sandstone. The weathering picks 

 out with great delicacy those parts which are more sus- 

 ceptible to solution and decay. 



WATER SUPPLY IN MILITARY AREAS.— The 

 Geological Survey has just issued an interesting pamphlet 

 entitled " Notes on Sources of Temporary Water Supply 

 in the South of England and Neighbouring Parts of the 

 Continent." This was written primarily to aid the Royal 

 Army Medical Corps of the First London Division Territorial 

 Force in finding drinking water at short notice by temporary 

 works. It is pointed out that all running streams are 

 highly dangerous as drinking water in a seat of war or 

 populated area, and wells, although not subject to the same 

 sweeping condemnation, are liable to suspicion, especially 

 when shallow. All water obtained from superficial deposits 

 is liable to contamination in these areas, and requires careful 

 testing before use. In choosing a site for a well, a warning 

 is given to avoid the neighbourhood of obvious sources of 

 pollution, such as farmyards, cemeteries, sewage works, 

 etc., and to make a trial farther up a valley than any of 

 these dangerous sites. 



On chalk areas running water is usually sparse, and the 

 water is trapped within the fissures of the rock. This 

 supply may be discharged by springs at the outcrop of 

 a relati^'ely impermeable stratum, or may be reached by 

 wells sunk below the plane of saturation. The chalk supplies 

 hard but usually pure water. 



These considerations apply to a large part of the war area 

 in Central and Northern France and Belgium, where the 

 strata are generally similar in age and composition to those 

 of the London and Hampshire basins, but the tract of ground 

 east of Valenciennes presents quite different problems. It 

 consists of highly inclined or vertical strata of Devonian 

 and Silurian ages, forming the hills of the Ardennes. In tliis 

 area recourse will doubtless be had to springs, many of 

 which are to be trusted. No water, however, from what- 

 ever source, should be used without testing. 



METEOROLOGY. 



By William Marriott, F.R.Met.Soc. 



THE WEATHER OF MARCH.— The general meteoro- 

 logical features of the month of March are very irregular, 

 but its main character is that of boisterousness and cold. 

 Sometimes a strong north-east wind is prevalent, which, 

 when it lasts many days, induces a rapid evaporation from 

 the soil, respecting which there are numerous old proverbs, 

 such as : — 



" A peck of March dust is worth a king's ransom." 

 " A dry and cold March never begs its bread." 



March was a very cold month in the years 1845. 1865, 

 1883, and 1892 ; and it was a ver>' mild month in the years 

 1841, 1859, 1882, 1893, 1896, 1903, and 1912. 



The average mean temperature at Greenwich for March 

 is 41°-9 ; in 1859 it was as high as 46°-8, while in 1845 it 

 was as low as 35° -6. The average maximum temperature 

 is 49° -8 ; the highest mean was 56° -9 in 1893 and the lowest 

 42° -7 in 1845. The average minimum temperature is 

 35° -1 ; the highest mean was 40° -5 in 1859, and the lowest 

 29° -3 in 1883. The absolute highest temperature recorded 

 was 71°-5 in 1848 on the 31st, and the absolute lowest 



13°-1 in 1845 on the 14th, and also in 1890 on the 4th. 

 The average number of days on which the temperature 

 falls to or below the freezing-point is ten. In 1845 there 

 were four days on which the temperature was continuously 

 below the freezing-point. 



The average rainfall for the month of March is 1-52 

 inches; the greatest amount was 4-05 inches in 1851, 

 and the least 0-17 inch in 1852. The heaviest fall in one 

 day was 1-21 inches in 1832, on the 14th. The average 

 number of " rain days " {i.e., on which 0-01 inch fell) is 

 13-2, the greatest number of days was twenty-two in 1848 

 and 1896,' and the least three in 1852. Snow falls on the 

 average on three days. Hail or " graupel " {i.e., soft hail) 

 usually falls on one or two days. The average amount of 

 bright sunshine at the Kew Observatory, Richmond, is 

 one hundred and six hours. 



The average barometric pressure in London for March is 

 29-955 inches, the highest mean was 30-374 inches in 1854, 

 and the lowest mean was 29-531 inches in 1909. 



" March many weathers." 



" March comes in like a Uon and goes out Uke a lamb." 



WEATHER FORECASTS BY CINEMATOGRAPH.— 

 In an interesting article on " Forecast Distribution," by 

 Mr. G. W. Smith, in the Monthly Weather Review, it is 

 stated that the display of weather forecasts on moving- 

 picture (cinematograph) screens is the latest method em- 

 ployed in the United States for giving the information 

 to the pubhc, and was successfully begun in March, 1912. 

 This means of forecast display is now used in eight cities. 

 Mr. Smith also says that the Weather Bureau has ever been 

 alert to take advantage of every opportunity tending to the 

 betterment of the forecast distribution, and is to-day 

 making the forecasts available to more than five and a half 

 million persons (mostly by telephone), exclusive of those 

 supplied through the daily newspapers, daily weather maps, 

 display of flags, and on moving-picture screens. 



MICROSCOPY. 



By J. E. Barnard, F.R.M.S. 



MICRO-ORGANISMS AND THE WAR— In all wars of 

 any magnitude, other than the one now in progress, the 

 loss of life from disease has been considerably greater than 

 that resulting from wounds. In the present war the bacterial 

 foes are being so efficiently dealt with that the state of 

 affairs is likely to be reversed, thanks to the efficiency of 

 the Army Medical Service and the great efforts that are 

 being made to lessen both medical and surgical infection. 



There are many causes operating to produce this result. 

 Of course, general hygiene has been very carefully attended 

 to, so that the sanitary conditions in camps and other places 

 where men are gathered together for training are very much 

 better than have ever been obtained before. At the same 

 time, the method of vaccination, particularly against 

 typhoid and tetanus, has been exceedingly efficient. In 

 the case of typhoid, which has been the most prevalent of 

 all epidemic diseases in previous campaigns, the result has 

 been nothing less than extraordinary, and the method of 

 anti-typhoid inoculation has proved a marvellous success. 

 No method in preventive medicine can be infallible, but 

 this one has approached as nearly to that state of affairs 

 as can be hoped for. It is very much to be regretted that 

 some people in this country — well-intentioned, it may be, 

 but sadly lacking in scientific insight — have tried to per- 

 suade men against being inoculated for typhoid. The results 

 are not only likely to be injurious to those who refuse to 

 submit to what is, after all, but a trivial infliction, but 

 constitute, at the same time, a serious danger to their 

 fellow-men. The Army Council has been well advised, 

 no doubt, in not taking any drastic steps to put an end to 

 the anti-vaccination propaganda. At the same time, there 

 is not the slightest doubt that in cases where the anti- 

 vaccinationists have been successful in fomenting a feeling 

 of resistance, fortunately not very many, the results have 



