i8 



NATURE 



[November 2, 191 1 



deals with Hibiscus cannabinus, popularly known as 

 Deccan or ambari hemp, and //. Sabdariffa, the Rozelle 

 plant ; it is published in the Memoirs of the Department 

 of Agriculture in India as vol. iv., No. 2, of the botanical 

 series. The investigation was primarily directed towards 

 analysing the ordinary crops with the view of eliminating 

 cross-fertilisation and securing uniformity of product. 

 Five varieties, showing differences in the seedling and early 

 vegetative stages, were isolated ; descriptions of these and 

 coloured figures are supplied. Two of the types are re- 

 garded as specially promising, and it is intended to develop 

 these by pure-line cultures. The account of H. Sabdariffa 

 is confined to comparative notes on pollination and the 

 descriptions of four varieties. 



The interesting chapter on the history of fossil botany, 

 chosen by Dr. D. H. Scott as the subject of his presi- 

 dential address to the Linnean Society at the close of the 

 last session, dates back three-quarters of a century, to a 

 time when Witham in England and Cotta in Germany 

 were prominent investigators, and the more illustrious 

 Brongniart was engaged upon his earlier researches. 

 Morphological elucidation was the guiding principle of 

 Brongniart 's studies, and in most cases he found it neces- 

 sary to discover the required morphological data himself. 

 His " Histoire des V^g^taux Fossiles " contains in the 

 introduction a definite recognition of four successive geo- 

 logical periods characterised by different types of vegeta- 

 tion. Witham 's chief service was to demonstrate the 

 early prevalence of gymnosperms, and he was also the first 

 to describe the structure of the historic fossil Lepido- 

 dendron Harcourtii, although it remained for Brongniart 

 to identify the ring of wood. To Cotta credit is due for 

 the foundation of the genus MeduUosa, and a virtual 

 recognition of its polystelic character. 



In the NaturivissenschaftUche Wochenschrift for 

 October i there is an article on the geological study of 

 earthquakes, by Dr. Erwin Scheu, whose name is well 

 known in connection with catalogues published by the 

 International .'\ssociation at Strassburg. The article deals 

 with macroseisms, or earthquakes which can be felt. 

 The intensities of these should be referred to a scale ; but 

 as seismologists are already troubled with sixteen different 

 scales of intensity, it is not clear why Dr. Scheu should 

 add to their number. He, however, suggests one which, 

 he remarks, might be suitable for Europe, but hardly suit- 

 able for the tropics. An earthquake which is not felt 

 should, according to the new scale, be indicated by the 

 numeral I, whilst one accompanied by complete destruc- 

 tion, which refers to a megaseism rather than a micro- or 

 macroseism, has an intensity of VII. In a map of 

 isoseists for the earthquake of J6keo, January, 1906, some 

 of them are, however, marked VIII and IX. In connec- 

 tion with the construction of isoseists, we are told that 

 the intensity of movement exhibited in hard rocks like 

 granite is greater than it is in materials like marl and 

 clay. So far as destructivity is concerned, our impression 

 has been that this is generally the reverse. The influence 

 of fault lines, as, for example, those in the Rhine Valley 

 and mountain ranges, upon the distance to which earth- 

 quake motion may be propagated is pointed out. Illustra- 

 tions are given of the destruction caused to buildings, and 

 the displacements, vertical and otherwise, of land surfaces. 

 Dr. Scheu 's article is distinctly popular, and as such 

 suggests phenomena to be observed at the time and after 

 the occurrence of an earthquake. 



The meteorological charts of the North Atlantic and 

 Mediterranean for November, issued by authority of the 

 Meteorological Committee, contain an instructive account 



NO. 2192, VOL. 88] 



of the behaviour of a heavy storm in the North Sea, ill 

 trated by synoptic charts. Between September 28 and 

 a small cyclonic system seems to have formed near 50" 

 and 30° W. ; on the morning of September 29 the chart 

 that day shows that the centre was about 57° N. 

 25° W., and was advancing towards the coast of Irel.i 

 increasing in velocity and intensity as it travelled < 

 wards. On the morning of September 30 the centre \ 

 near Spurn Head ; during the gale an extreme force of 

 (Beaufort scale) was recorded at several stations on 

 East Coast, and at 6h. p.m. the centre passed over 

 north of Holland. An interesting point in this storn. 

 that apparently the wind force experienced by vessels in 

 the North Sea was greater than that at many of the lancf 

 stations in telegraphic communication with the Met 

 ological Office. The numerous casualties to shipp 

 would also seem to show that the high seas must h 

 been exceptional. 



In Symons's Meteorological Magazine for October Mr. 

 W. Sedgwick continues his interesting notes on the weati 

 in the seventeenth century : part iii., autumn (see Nati 

 june 1). He points out that at this season of the y> : 

 sueJi phenomena as heat waves, severe frosts, &c., are not 

 likely to occur, at any rate near London. It is not sur- 

 prising, therefore, that Evelyn and Pepys made fe\v> r 

 comments than in the case of the other seasons. To those 

 who still firmly believe that the climate of England ha? 

 changed, the month of October presents special inter 

 owing to the comparatively high temperatures experieii 

 in that month in recent years. In a paper read before 

 the Royal Meteorological Society on April 19, on varia- 

 tions in English climate, it was shown that for the last 

 fourteen years (1897-1910), except only in 1905, the 

 temperature was above the average in October. So far 

 as can be judged from the chronicles above referred t^. 

 this variation in recent years is merely a periodic char 

 as they do not show that the weather of that month v . 

 noticeably colder than at the present time. Frequent refer- 

 ences are made to the pleasant weather experienced ; only 

 one October (1692) was referred to as a cold month ; Pepys 

 described that of 1668 as *' the most summer weather that 

 was' ever seen." The general character of the weather in 

 November also, as described by Evelyn, was very similar 

 to that of the present time. 



In a paper by Prof. Henry Louis on the mutual develop- 

 ments of metallurgy and engineering, read before the 

 University of Durham Philosophical Society, and published 

 recently in its Proceedings, much interesting information 

 is given about the history of metallurgical processes. It 

 seems to be fully proved that the Assyrians were not only 

 well acquainted with iron, but had attained some consider- 

 able skill in its manufacture, having advanced far enough 

 to make chain mail; thus, so far back as 900 B.C., iron 

 manufacture had long passed the rudimentary stages. The 

 only other common metals known to the ancients were 

 lead, copper, and tin, all of which are easily reduced from 

 their ores ; brass was known for a very long time before 

 it was discovered that zinc was one of its constituents, it 

 being always made direct from zinc ore ; Roman brass 

 coins have been analysed, and found to contain more thart 

 25 per cent, of zinc, so that the material was certainly 

 known to them, although they did not know its true com- 

 position. The metallurgy of lead was relatively far 

 advanced ; quite a number of pieces of lead of Roman age 

 have been found in this country, the earliest date about 

 44 A.D., and several of these are marked " ex. arc," or 

 desilverised ; it is also evident from the composition of 

 articles of Roman lead that the metallurgists of that day 



