0o4 



NATURE 



[April 2?>, i8Si 



rently do not sleep at all. The leaves of Euphorbia jaeqiiiniis- 

 flora depend vertically at niifht, whereas thoss of a dwarfish 

 Brazilian species ri^e vertically up at night. The leaves of this 

 Euphorbia stand opposite one anoher — a position which is 

 rather rare in the genus ; and the rising movement may be 

 of service to the plant, as the upper surfaces of the opposite 

 leaves mutually protect one another by coming into contact. In 

 the genus Sida the leaves of two species rise, while those of a 

 third Brazilian species sink vertically down at night. Two 

 species of Desmodium are common plants near Fritz Muller's 

 house : in one the le iflets move simply downwards at night ; but 

 in the other not only do the three leaflets move vertically down, 

 while the main petiole rises vertically up, as is likewise the case 

 with D. gyrans, hut in addition the lateral leaflets rotate so as to 

 stand parallel with the termmal leaflet, behind which they are 

 more or less completely hidden. This, as far as I have seen, is 

 a new kind of nyctitropic movement ; but it leads to a result 

 common to several species, namely, that of packing the three 

 leaflets closely together and placing then in a vertical position. 

 Down, Beckenham, Kent, April 14 Charles Darwin 



Spectrum of the Star LI. 13412 



The spectrum of the star LI. 13412 appears to be in some 

 respects unique. It consists mainly of three bright lines having 

 wave-lengths of 545, 4S6, and 466 millionths of a millimetre. 

 Four other stars have hitherto been found whose spectra are of 

 this character. Three of them are in Cygnus, and have lines 1 

 whose wave-lengths are 580, 56S, 536, and 467. The fourth 

 star, Oeltzen 17681, has lines at about 582 and 470 (Nature, 

 vol. xxii. p. 483). The line or band at 467 appears to be com- 

 mon to all, and that at 580 to the last four. The line at 486 in 

 LI. 13412 coincides with the F line of hydrogen, but is not 

 visible in the other stars. The line at 545 is also absent in 

 them. This star therefore appears to resemble the others in 

 kind, but not in the material of which it is composed. It is 

 also much brighter than the others, so that it is not a difficult 

 object with a small telescope. Its position for 1880 is in R.A. 

 6h. 49'3m. and Dec. - 23° 47'. It is easily found as a seventh 

 magnitude star about 15' north of o' Canis Majoris. 



Cambridge, U.S., April 14 Edward C. Pickering 



The Indian Winter Rains 

 In Nature, vol. xxiii. p. 400, Mr. F. Chambers very 

 properly points out that the winter rains of Northern India, 

 though usually heaviest in years when the mean pressure is above 

 the average, are yet coincident with short periods of low rather 

 than of high pressure. The way in which Mr. Chambers accounts 

 for the low pressure seems, however, rather far-fetched. It is 

 true that on one or two of the A'oerican weather charts storm 

 tracks are shown extending from the Mediterranean to Northern 

 India or the Bay of Bengal, but these paths are drawn with 

 dbtted lines indicating that they are doubtful, and, considering 

 the absence of meteorological stations in the greater part of the 

 area between the Mediterranean and India, a id the nature of the 

 intervening country — especially Afghanistan with its high moun- 

 tains — I should say the evidence up ni the strength of which the 

 American chartographer laid down thde storm tracks, was of 

 the slightest possible description. The winter rains are however 

 accompanied by a cyclonic movemeat of the air over Northerii 

 India, and I wish to point out thai, whether the cyclonic disturb- 

 ance be a European or Transatlantic visitor, as Mr. Chambers 

 supposes, or a native of the Indian region, gener.ited by the 

 rainfall, as Mr. Eliot has taught in his report for 1S77, the "old 

 notion " of the connection of the rains with the upper anti- 

 monsoon current is by no means explode.l. The progress of the 

 disturbance and of the rainfall is usually from north-west to 

 south-east, and the rainfall is heaviest, as a rule, on the eastern 

 side of the disturbance. The winds which brirg the rainfall 

 therefore come from some southerly quarter, and as northerly 

 winds generally continue blowing in the extreme south of India 

 at the time when these disturbances occur in the north, the 

 southerly rainy winds must be derived from an upper current 

 which descends in the anti-cyclone or region of high pressure in 

 the centre and south of India, or in the zone between the south 

 of India and the equator. Mr. Bl mford's modification of his 

 former views regarding the origin of these rains appears from his 

 remarks and the accompanying charts in the Meteorological 

 Rfeport for 1878 to be merely that the indraught towards the 



region of precipitation is not confined to Northern India, but is 

 occasionally, though rarely, felt as far south as Ceylon. 



In a letter of mine that appeared in Nature for the following 

 week (p. 409), there was a mistaken inference from Mr. Stan- 

 ford's investigation regarding the *' Barometric See-saw " between 

 India and West Siberia that I beg your permission to correct. 

 The mean pressure at sea-level in the Indo-Malayan and West 

 Siberian regions appears from Mr. Buchau's charts to be nearly 

 the same both on the average of the year and in January and July. 

 Also no wind blows directly from the one region to the other. We 

 cannot therefore infer anything regarding the strength of the winds 

 from Mr. Blauford's results, but we may regarding temperature. 

 Theproperinferencesof this kind from the results arrived at by Mr. 

 Blauford and Mr. Archibald appear to be these : — (i) The range 

 of temperature in the 11 -year period is greater in Siberia than in 

 surrounding countries ; (2) Siberia is coldest, compared with 

 neighbouring countries, at times of maximum sun-spot ; (3) This 

 relation is most marked in winter ; and (4) near the coasts of 

 the Pacific (Nertchinsk, Pekin, Zi:ka-wei), the Indian (all the 

 Indo-Malayan stations, especially those nearest the sea), and the 

 Atlantic (Loudon) oceans, where presumably the range of tem- 

 perature is less than in the heart of the continent, the variation 

 of the barometer in the 1 1 -year period is opposite to that obsei-ved 

 in Siberia. S. A. HiLL 



Allahabad, March 29 



Palaeolithic Man 



It is desirable that further search should be made for imple- 

 ments made by man in the deposits of this country assumed to 

 be older than the well-known and accepted implementiferous 

 river-gravels. 



In the gravels belonging to the Thames, in and near London, 

 pala-olithic implements are of njt infrequent occurrence. In 

 my own collection I have more than 120 examples — with few 

 exceptions found by myself — and I know of at least another 

 hundred specimens found chiefly by London friends who have 

 availed themselves of hints given by me. 



My object now is to direct attention to the fact that the imple- 

 ments are not only found in and near London in the lower and 

 middle terraces of gravel some 25 to 70 feet above the ordnance 

 datum, but at far greater heights. Some of these heights near 

 London may, and others no doubt do, belong to the Thames or to its 

 tributaries, but they all (in difierent degrees) appear to point to a 

 [ more remote time than the period when the lower terraces of the 

 Thames and its tributaries were formed. Some of the imple- 

 ments now found in the loiver gravels are clearly "derived" 

 from more ancient deposits. For instance, I have one example 

 white in colour and highly porcellaneous : — the white colour has 

 been brought about by the decomposition of the flint in some 

 ancient loam or clay, and not from the gravel in which the im- 

 plement was found : this is proved by several more or less 

 highly-polished accidental fractures at the edges of a different 

 colour from the general white surface : these coloured fractures 

 are more recent than the white facets, and date from the last 

 deposition of the implement in the lower terrace : the white 

 abraded flakings belong to a highly remote time. Dr. John Evans 

 records the finding of an implement in the Thames gravel at 

 Highbury, at 102 feet, whilst I have found one (also near 

 Highbtu-y), at an elevation of 144 feet. Last summer I found 

 an implement on the eminence at the ncrt 1 of, and overlooking 

 Ealing Dean, at a height of 164 feet. This is 72 feet higher 

 than the implementiferous beds of Ealing Dean described by 

 General Pitt Rivers, and between 80 and 100 feet higher (in one 

 instance 104 feet higher) than the implement-bearing gravels at 

 Acton described by the same gentleii.an. The gravel at the 164- 

 feet elevation forms an isolated patch on the extreme top of a 

 hill. I watched the excavations here (which were shallow) for 

 road-jiaking, wi'h great care, and with the implement I found 

 several flakes. These heights agree well with the heights of some 

 of the implementiferous gravels found capping the cliffs in the 

 South of England, also with the'Erith position at Northumber- 

 land Heath, where Mr. F. C. J. Spurrell found an implement at 

 an elevation of 175 feet. 



Most geologists know the high gravels overlooking Hertford, 

 Ware, and Amwell ; their altitude is froji 130 to over iSo feet 

 above the ordnance datum. Gravel from the two first of these 

 places [is Iirought to London for |ballast in thousands of tons. 

 A year or two ago great quantities of gravel from Hertford 

 were brought to Finsbury Park by the Great Northern Rail- 

 way, and in the gravel thrown down near Finsbury Park 1 



