220 



KNOWLEDGE. 



June, 1913. 



RAISED BEACHES AND PALAEOLITHIC MAN.— In 

 the April Geological Magazine Mr. H. Dewey describes the 

 raised beach of North Devon and discusses its relations to 

 other Pleistocene deposits and to Palaeolithic man. The 

 raised beach forms a shelf and notches the cliffs about ten to 

 fifteen feet above sea-level. Between Croyde Sand and 

 Saunton Down the beach lies on a shelf, and is overlaid by a 

 variable thickness of current-bedded sand, the contained 

 shells of which indicate a warm temperate climate. The 

 raised beach deposit consists of pebbles of slate, sandstone, 

 vein-quartz, quartzite, and chalk-flints. Erratic boulders of a 

 red granite lie on the platform. The granite closely resembles 

 a gneissose granite from Ross-shire ; and if this identification 

 be correct, ice is the only conceivable transporting agency. 

 The sand is overlaid by a bed of " head," which in turn is 

 covered by a bed of large rounded stones. A bed corre- 

 sponding with the latter, occurring at Fremington, contains 

 glaciated stones in a brown loamy clay, and indicates an 

 arctic climate during its formation. A similar bed of 

 glaciated stones overlying " head " was discovered by Mr. 

 Barrow in the Scilly Isles. In the Coombe rock of Southern 

 England and France, which is equivalent and contemporan- 

 eous to the "head" of Devon and Cornwall, Palaeolithic 

 implements of Mousterian type have been found. 



Mr. Dewey comes to the conclusions that the deposits over- 

 lying the raised beaches were formed during a period of 

 variable climate — arctic at first, then warm temperate, finally 

 reverting to arctic — and that early Palaeolithic man lived 

 during the inter-arctic period. He is later than the chalky 

 boulder clay and the raised beach, and earlier than the 

 boulder clay of Glamorgan and South Ireland. 



QUANTITATIVE STUDY OF ACTIVE VOLCANOES. 

 — The great quantitative geological investigations which we 

 owe to the Geophysical Laboratory of the Carnegie Institute 

 at Washington are now being supplemented by a study of the 

 physics and chemistry of active volcanoes (Year Book No. 11, 

 1912). The crater of Kilauea in Hawaii is the one selected 

 for this purpose. During the past summer it was found 

 possible to descend into the crater and collect the volatile 

 ingredients directly from the lava. These gases were 

 collected and sealed in glass tubes without having come into 

 contact with the air at all, and sent to Washington for 

 detailed study. A very important observation is, however, 

 available, and that is that the temperature of the lava in the 

 active basin varies from day to day, and that this variation 

 depends on the quantity of gas emitted. The temperature rises 

 with an increase of gas emission, and falls when the volume 

 of gas diminishes. 



The composition of the smoke cloud above the volcano, 

 which contains much non-gaseous matter, was also studied, 

 and samples of the liquid lava were taken directly from the 

 molten lake. It is hoped to determine the character of the 

 chemical reactions within the gases, between the gases and 

 the liquid lava, and between the gases and the air. Arising 

 out of the recent contention of Briin and others that volcanic 

 eruptions are essentially anhydrous (see ■ Knowledge," 

 April, 1911, p. 352), it is mentioned that from one of the gases 

 collected directly from the boiling lava no less than half a 

 pint of water was condensed on cooling. 



METEOROLOGY. 



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



DEATHS BY LIGHTNING.— Most people imagine that 

 the number of persons killed by lightning each year is very 

 great. This impression is largely due to the lack of reliable 

 information and to the inherent dread of thunderstorms, and 

 is far from being correct. Dr. A. Jex-Blake, in a recent course 

 of lectures delivered before the Royal College of Physicians 

 on " Death by Electric Currents and by Lightning," gave 

 some statistics on the subject from which he showed that during 

 the ten years 1901-1910, the Registrar-General had reported 

 one hundred and twenty -four fatal instances in lightning 

 stroke in England and Wales — one hundred and eight in men 



and sixteen in women — a yearly average of only 12-4 deaths, 

 or 0-36 per million living. In the twenty-nine years 1852-1880 

 there were five hundred and forty-six such deaths, the yearly 

 average for that period being 18-8, or 0-88 per annum per 

 million living. The number of these deaths varied widely in 

 different years ; three people were killed by lightning in 

 1863 and forty-six in 1872. The annual death-rate from 

 lightning also varies widely in different parts of England. In 

 the north Midlands from 1852-1880 it was 1-8 annually per 

 million living, in the Metropolitan district only 0-13 (Lawson) 

 — a figure that should be of comfort to anybody who is in 

 London during a thunderstorm. On the Continent much 

 higher yearly death-rates are found. In Hungary the annual 

 death-rate from lightning is said to be sixteen per million 

 living (Milham) ; in Styria and Carinthia about ten per million ; 

 in Prussia 4-4; in France and in Sweden three; in Belgium 

 two, so far as the imperfect statistics available go (McAdie 

 and Henry). Inthe United States of America the annual death- 

 rate per million is high — about ten — in consequence of the 

 frequency of thunderstorms on the one hand and of the large 

 percentage of the inhabitants engaged in outdoor labour on 

 the other ; about seven hundred or eight hundred deaths 

 from lightning were estimated to occur in the United States 

 every year by Henry in 1900 in a population of seventy-six 

 millions. 



Many more people are struck by lightning than are killed. 

 For example, Jack records an instance in which a church was 

 struck : three hundred people were in it, one hundred were 

 injured and mostly made unconscious, thirty had to take to 

 their beds, but only six were killed. Weber gives an account 

 of ninety-two people struck in Schleswig-Holstein : ten 

 were killed, twenty paralysed, fifty-five stupefied, and seven 

 only slightly injured. In 1905, a tent with two hundred and 

 fifty people in it was struck, and sixty were left on the ground 

 in various states of insensibility ; one was killed outright, 

 another breathed for some minutes before dying, the rest 

 recovered. As many as eleven and eighteen persons have 

 been killed bj*'a single stroke of lightning. Vincent mentions 

 a stroke thMt threw down one thousand two hundred and 

 killed five hundred and fifty-six out of a flock of one thousand 

 eight hundred sheep. Dechambre believes that children are 

 perhaps less liable to be struck than adults ; but statements 

 such as these are really not capable of proof or disproof. 



STORMS ON THE ATLANTIC, JANUARY, 1913.— 

 The month of January, 1913, was probably the stormiest 

 month on record on the North Atlantic Ocean. Mr. R. E. 

 Harris has given an account of the storms of this month, 

 together with some synoptic charts over the North Atlantic at 

 Greenwich mean noon, and also barograms from several 

 vessels. 



During the first half of the month several unusually severe 

 storms crossed the North Atlantic, the most severe of which 

 can be traced on the synoptic charts from the 8th to the 11th. 

 This storm was only a moderate depression with two centres 

 at noon of the 8th, the lowest barometer at the primary centre 

 over New York being 29-60 inches. At the same time a 

 severe storm was central near latitude 49° N., longitude 

 25° W., and was causing winds of force eight to twelve 

 (Beaufort scale) over a wide area north of the Azores between 

 the fifteenth and forty-fifth meridians. By noon of the 9th a 

 rapid development in the western storm had occurred, and it 

 was central near latitude 45° N. and longitude 48° W., with 

 lowest barometer 28-72 inches. Winds of force seven to 

 twelve were prevailing west of the fortieth meridian and north 

 of the thirty-fifth parallel. During the night of the 9th and 

 10th the storm was at its height, and remarkably low 

 barometer readings were recorded, the lowest, 26-96 inches, 

 being registered on the SS. Manchester Inventor, at 1 a.m., 

 on the 10th, at 52° N., 25° 30' W. This is probably the 

 lowest reading ever made on the North Atlantic. By noon 

 the storm was central near 51° 30' N., 27° W., with lowest 

 barometer 27-76 inches. Winds of hurricane force were 

 experienced by many vessels north of the fortieth parallel, 

 between the forty-fifth and fourteenth meridians. Within 

 this area ten ships reported winds of force twelve, thirteen 



