43© 



NA TURE 



\_Augiist 30, 188; 



In the cycle as arranged above, the first year is that which 

 contains the year of maximum svmspot, and the eighth that of 

 minimum sunspot. 



With the figures in the text, the maximu n winter rainfall 

 occurs on an average rather more than a year before the minimum 

 of sunspots, and the minimum of rainfall appears either to coincide 

 with, or to follow the maximum of the sunspots, at about an 

 equal interval. 



While, therefore, the facts are so far favourable to a close 

 connection between sunspots and rainfall in tipper India, they 

 do not lead so much to the conclusion that the former direclly 

 affect the latter, as to their both being effects of some common 

 and as yet undetermined cause. 



It should be further noticed, both as a result of this investiga- 

 tion, and an example of one of the "new and unsuspected 

 truths" which Mr. Blanford says are often incidentally brought 

 to light, that the variations of the summer and winter fails ore 

 almost exactly contrary to each other, and as this has been found 

 to occur not only in the years of the mean cycle, but also in indi- 

 vidual years, it has been concluded by Prof. Hill thai in Northern 

 India the -winter rains are excessive ■when tie summer rains arc 

 defective and vice versa. 



This contrary variation, which is of itself a valuable discovery, 

 is moreover shown to be due in some measure to a reaction of 

 the winter on the summer rainfall. Thus, in years of heavy 

 winter rainfall in Northern India, and therefore of heavy snowfall 

 in the Himalayas, an excess of barometric pressure attended by 

 diminished temperature, is found to occur during the earlier 

 months of the year, which causes the air to move outwards from 

 the centre of relatively highest pressure, and so bar the approach 

 of the Arabian Sea current from the south-west, as well as the 

 Bay of Bengal current from the south-east, and by thus com- 

 pelling them to part with their moisture in other districts, such 

 as the hills of Central India, or East Bengal and Burmah respec- 

 tively, causes deficiency and drought over the Punjab and North- 

 West Provinces, or Western Bengal. 



On the other hand, in years of defective winter rainfall, the 

 temperature is generally high, and the pressure low, in the early 

 months of the year ; while the currents from the south-east up 

 the Ganges valley appear in full strength, and are accompanied 

 by early and abundant summer rains. 1 



Mr. Blanford has partly attributed the high atmospheric pres- 

 sure which occurs in the years of heavy snowfall, to the cooling 

 thereby produced, but as this abnormally high pressure some- 

 times extends right down the Bombay coast, it is plain that the 

 snowfall is not the only determining cause, and that we must 

 look to some more general cause to explain the matter. Prof. 

 Hill speculates very intelligently on this cause, but as the specu- 

 lation requires confirmatory evidence, it will be as well perhaps 

 not to dwell on it at present. 



It may, however, be observed that this speculation accounts 

 satisfactorily fur the double oscillation of the Bengal summer 

 rainfall with its maxima at both sunspot epochs, as well as the 

 double oscillation of the annual rainfall of Southern India, 

 noticed by the late Mr. J. A. Broun, F.R.S., in Nature, vol. 

 xvi. p. 334 (which, unlike that of Northern India, is solely 

 due to the summer monsoon current) with its minima at both 

 epochs, two remarkable facts, which might at first sight appear 

 to be almost irreconcilable, if not unaccountable. 



Before leaving this interesting and suggestive paper, it should 

 be remarked that the variation in the winter rainfall of Northern 

 India is shown to be closely connected with the curve of air- 

 temperature in the tropics calculated up to 1862 by Dr. Kbppen, 

 and continued up to 1877 by Prof. Hill from Indian observa- 

 tions alone. 



The following table gives the epochs of maxima and minima 

 of both elements, and the conclusion can, we think, scarcely be 

 resisted that there is a causal connection between them, since in 

 every case but one, the rainfall epochs slightly follow those of the 

 temperature : — 



Maximum and Minimum Epochs of Tropical Temperature and 



Winter /vain 



Minima Maxima. 



rature. Rain. Temperature, Rain. 



1836-9 ... 1837-8 ... 1842-7 ... 1842-7 



1847-7 -•• 1848-1 ... 18547 ... l855'o 



iS5S-4 ... 1860-6 ... 1865-1 ... l8( J 5 



1874-8 ... 1874-7 ... (1876-3) ... (1876-9) 



1 Thl editions are now so universally recogni-ed. as almost 10 



form a canon of Indian metecrology. 



Similar variations are shown to exist in the winter rainfall of 

 other parts of the world, as well as in the humidity of Russia 

 and Siberia, which favour the hypothesis long entertained both 

 by Prof. Hill and the writer, that "the winter rains in Northern 

 India occur simultaneously with an increase in the quantity of 

 aqueous vapour in the atmosphere over Eastern Europe and 

 Western Asia, and that the cause of both may possibly be found 

 in an unusually high temperature in the tropics, whereby the 

 evaporation of the waters of the ocean is accelerated and the 

 upper current of moist air known as the anti-trade has its velocity 

 increased." 



SCIENTIFIC SERIALS 



American Journal of Science, August. — Principal characters I 

 American Jurassic Dinosaurs, part vi. : Restoration of Bronto- 

 saurus, with plate, by Prof. O. C. Marsh. The restoration is 

 effected by bones belonging almost exclusively to a single indi- 

 vidual, which u hen alive was about fifty feet long ; chief charac- 

 teristics : Lug flexible neck, very short body, massive legs and 

 feet, the latter plmtigrade, and leaving footprints about a square 

 yard in extent, very large tail with solid bones, remarkably 

 small head, smaller in proportion to the body than that of any 

 other known vertebrate, skull being less in diameter or weight 

 than the fourth or fifth cervical vertebra. The living auimal 

 must have weighed over twenty tons, and appears to have been 

 a stupid reptile of slow motion, without offensive weapons or 

 dermal armature, amphibious in habits, feeding on aquatic and 

 other succulent plants. — The evolution of the American trotting 

 horse, by Francs E. Nipher. The minimum time of trotting a 

 mile, in a previous paper determined at 93, is here reduced to 

 91 second-, and it is suggested that the trotter will very probably 

 finally surpass the race-horse in speed. — On concave gratings 

 for optical purposes, by Henry A. Rowland, Professor of 

 Physics, Johns Hopkins University, Baltimore. — Glacial mark- 

 ings of unusual forms in the Laurentian Hills, by Dr. 

 Edmund Andrews. Several illustrations are given of the 

 peculiar marks here described, which are chiefly curved 

 stria?, serrated striae, and curious scoop-marks, both striated 

 and unstriated, very difficult to explain on any theory of 

 glacial action. — Response to the remarks of Messrs. Wachsmuth 

 and Springer on the genera Glyptocrinus and Reteocrinus, by S. 

 A. Miller. — On the present status of the eccentricity theory of 

 glacial climate, by W. J. McGee. In reply to recent critics the 

 author urges several arguments in defence of Croll's theory of 

 secular variations in terrestrial climate. — On the commingling of 

 ancient faunal and modern floral types in the Laramie group, by 

 Charles A. White. — Notes on some fossil plants from Northern 

 China, by J. S. Newberry. From the general character of the e 

 plants, which were collected by Mr. Arnold Hague, the author 

 considers that Pumpelly and Richthofen's estimates of the great 

 area and value of the North China coal and iron deposits are by 

 no means unwarranted. The plants, all of the Carboniferous 

 age, seem to prove that the Chinese coal basins belong to two 

 great geological systems, one answering to that of the European 

 and American coal-measures, the other probably referable to the 

 Rhcetic and Lias. — Review of De Candolle's " Origin of Culti- 

 vated Plants," with annotations on certain American species, 

 by Asa Gray and J. Hammond Trumbull. — On the supposed 

 human footprints recently found in Nevada, by O. C. Marsh. 



The Journal of the Franklin Institute, August. — Cranes ; a 

 study of types and details, by Henry R. Towne. — A remarkable 

 error in the common theory of the turbine water-wheel, by J. P. 

 Frizell. — Beton in combination with iron as a building material, 

 by W. E. Ward.— The grindstone, by J. E. Mitchell.— The 

 Glover tower and the working of sulphuric acid chambers, by 

 Moses A. Walsh. — On radiant matter spectroscopy, a new- 

 method of spectrum analysis, by William Crookes, F.R.S. — 

 The cause of evident magnetism in iron, steel, and other mag- 

 netic metals, by D. E. Hughes, F.R.S. — National Exhibition of 

 Railway Appliances, Chicago, 111. — Obituary, Benjamin Howard 

 Rand, Kranklin Institute. — Notes. — Induced currents in recipro- 

 cal movements. — Twinkling of stars during auroras. — Spanish 

 copper tubes. — Photozincography. — Orange peel. — Constitution 

 of the sun. — Colour of distilled water. — Deep-sea explorations. 

 — Generation of inflammable gases in the diffusion of beets.— 

 Amber. 



Journal of the Russian Chemical 'and Physical Society, vol. 

 xv. fasc. 5. — On the formation and properties of oxide of 



