Jan. 3T, 1878] 



NA TURE 



275 



give the averages in the table, and to variations in the number of 

 clear days in each month, the changes from year to year are very 

 irregular, but on the whole there is a decided, increase from 1870 

 to 1876. The sudden fall from 1873 to 1874 must be attributed, 

 Mr. Hill thinks, to the greater diathermancy of the clear air at 

 three of the stations in the former than in the latter year. It is 

 worthy of note that 1873 was a very dry year at all the stations, 

 but that 1874 was much wetter than usual except at Ajmere, 

 where it was drier than 1873. At this station the solar radia- 

 tion temperature shows a rise instead of a fall between 1873 and 

 1874. 



With regard to the change of anemometer referred to by Mr. 

 Blanford, Mr. Mill says that fortunately, in the present case, any 

 other pair of stations, such as Madras and Vizagapatam, will do 

 as well. With reference to the possible variation of the winter 

 rain of Europe according to the supposed variation in the force 

 of the anti-trade, Mr. Hill notices that the rainfall of London 

 shows such a variation, though not very clearly. He adduces 

 some figures in support of this. 



In Mr. Hill's paper, vol. xvi., the word fiiinimum, p. 5o5> 

 second column, eighteenth line from bottom, exact, same column, 

 third line from bottom, and commutative, p. 506, first column, 

 fourth line from bottom, should be maximum, excess, and 

 cumulative respectively. 



Mr. Hill also writes that the large double oscillation in the 

 decennial period of rainfall in Southern India, pointed out by 

 Mr. J. A. Broun, in Nature, vol. xvi. p. 333, will probably be 

 found to exist in other parts of the country, including the north. 

 One of the longest continuous registers of rainfall in existence for 

 any station in Upper India is that kept by the G.T. Survey Office 

 at Mussoorie, in the Himalayas, lat. N. 30° 28', long. E. 78° 7', 

 altitude 6,500 feet. The rain has been recorded since 1854, but 

 only during the rainy season. May to October, inclusive ; and 

 the register down to 1873 ^^^ been already published by Mr. 

 J. B. N. Hennessey, in the Proc. R.S., vol. xxii. No. 152. 

 Mr. Hennessey's table, extended down to the present year by 

 means of a register kept by the Civil Surgeon, gives a general 

 mean for the twenty-four years of 83 "2 inches, and an absolute 

 range of no less than 104 inches. 



When the yearly rainfalls are arranged in series of two, three, 

 &c. , up to twelve years each, beyond which number it is impos- 

 sible to extend the series without taking as representative the 

 uncorrected falls of single years, it becomes evident that the 

 great periodic oscillation that underlies the irregular variations 

 must complete its cycle in from nine to twelve years, for the 9-, 

 10-, II-, and 12-year series, all show a large amplitude of oscil- 

 lation, and in the II -year series the maximum and minimum 

 occur at nearly opposite phases of the cycle. It is also evident 

 that in the 6-year series the conditions are the same, the only 

 difference being that the amplitude does not appear quite so 

 great. 



Calculating the coefficients of the equation of sines for the 

 ten-and-a-half-year period, as Mr. Broun has done, we get for 

 the variable part of the Mussoorie rainfall — 



7 = ii"4 sin -h i4"o sin (29 -f 337°). 



This may be compared with the equations given in Mr. 

 Broun's article for Madras and Trevandrum,^ for in all these 

 equations » = o for the years 1838-5, 1849, l859'5, 1870, &c. 

 The diffijrence of the two angles, 259° and 337°, causes a dif- 

 ference of more than a year in the epochs of the maxima 

 and minima of the secondary oscillations, otherwise there is a 

 wonderful similarity between the formulae for two such widely- 

 separated stations as Mussoorie and Trevandrum. * 



Mr. Hill thinks it most likely that the oscillation of the five- 

 yearly period is either purely accidental or the effect of some 

 cause not yet understood. 



Mr. Archibald, writing on the subject of Cyclone Generation, 

 directs attention to an exceedingly interesting article in the 

 /'/(7«f«- of October 30, entitled "A Cyclone Study," in which 

 the author brings forward some very strong additional proof 

 in confirmation of the " condensation theory " held by Messrs. 

 Eliot and Blanford as opposed to the ' ' parallel wind theory " 

 advocated by Drs. Hann and Thau, and Messrs. Meldrum and 

 Willson. After giving a clear account of the main points of 

 difference between .the above theories, the writer then proceeds 



' Viz. : J/ = 5-4 sin (tf + so') -J- 4-6 sin (aS -|- 232°), 

 and jy = 5"6sin(e - 17*) -)- 8-4sin(2d + 259°) . 



" The above equation for Mussoorie gives the maxima in i86o'3, i87o'8, 

 &c., and the minima in 1857*2, 1867 '7, &c. The first term alone would 

 give the maxima in i86qi, 1870-6, &c., and the minima in 1855-9, 1866-4, 

 1876*9, &c. 



to trace the history of the last cyclone in the Bay of Bengal, the 

 Madras cyclone of May last, from its origin to its final disappear- 

 ance, pointing out certain circumstances as giving strong support 

 in favour of the condensation theory, and as completely dis- 

 posing of the parallel wind theory — at all events as far as regards 

 this particular cyclone. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



Cambridge. — The Mathematical Tripos' list this year con- 

 tains ninety -four names. There are thirty-one classed as Wranglers, 

 thirty as Senior Optimes, twenty-nine as Junior Optimes, and 

 four ^grotant The Senior Wrangler is Mr. Ernest William 

 Hobson, Scholar of Christ's College, eldest son of Mr. W. 

 Hobson, proprietor and editor of the Derbyshire Advertiser. 

 He was educated at Derby School, and in 1874 obtained 

 an open scholarship at Christ's College. During his under- 

 graduate career he obtained the first place among the students in 

 the college examinations in mathematics. His college tutor 

 was Mr. Peile, and his private tutor Mr. E, J. Routh, of St. 

 Peter's College. Next to him are Mr. John Edward Aloysius 

 Steggall, scholar of Trinity College, and Mr. Christopher 

 Graham, scholar of Caius. 



During the present term three courses of lectures on chemistry 

 will be delivered. A general course by Mr. Main at St, John's 

 College ; a course by Mr. Lewis at Downing College ; and a 

 course on the non-metallic elements by Mr. Pattison Muir at 

 Caius College. 



Munich, — The university is becoming in point of numbers 

 one of the foremost in Germany. The calendar for the present 

 year shows an attendance of 1,360, of whom 1,014 are from 

 I3avaria and 346 from other countries. In the theological faculty 

 there are 82, in the legal 387, in the medical 341, in the philo- 

 sophical (history, philology, &c.) 246, (science) 151, together 

 with 1 36 pharmaceutical chemists, and 1 7 in forestry and agri- 

 culture. The corps of instructors numbers 114, The university, 

 although but fifty-two years old, has been well supported by the 

 State, and possesses a large variety of laboratories, cabinets, &c., 

 and a library of 20,000 volumes. 



SOCIETIES AND ACADEMIES 



London 



Royal Astronomical Society, January il. — Dr. Huggins, 

 F.R.S., in the chair. — A paper by Mr. W. F. Denning on 

 suspected repetitions or second outbursts from radiant points, 

 and on the long duration of meteor showers, was read, showing 

 that a radiant in some cases continues active during three or four 

 months, and sometimes a second outburst occurs after an interval 

 of six months, so that meteors may be seen coming from the 

 same radiant at opposite sides of the earth's orbit. Capt. Tupman 

 commented on this paper at some length, and pointed out some 

 of the difficulties these conclusions presented. — Dr. Wentworth 

 Erck read a paper on a combined position and setting circle, 

 rendering the declination circle unnecessary on large Newtonian 

 equatorials. He also showed a small and singularly portable 

 equatorial mounting, and read a note on a spectroscope made by 

 Mr. Grubb for Prof. Young, showing certain improvements. 

 Mr. John Browning admired the ingenuity of these, and explained 

 which of them were new and which were not. — Mr. A. A. 

 Common read a note on the satellites of Mars and Saturn. — A 

 note was read describing the failure of the Melbourne telescope 

 to deal with the satellites of Mars.— Mr. S. Waters read a paper 

 on the distribution of the fixed stars in space. — Mr. Christie read 

 a paper on specular reflection from Venus, the purport of which 

 was that his recent observations of the planet with the polarising 

 eye-piece emphatically corroborated those made in 1876. By 

 means of this eye-piece the light of the disc is gradually reduced ; 

 and he found in every examination that the last part of the disc 

 to disappear was situated at a point which was found by calcula- 

 tion to coincide with the point indicated by the theory of specular 

 reflection, thus confirming Mr. Brett's original description of the 

 phenomenon. Mr. Christie had the assistance of Capt. Tupman 

 in his recent observations. Mr. Neison suggested certain other 

 explanations of the appearances described, and after further dis- 

 cussion the meeting adjourned. 



Zoological Society, January 15. — R. Hudson, F.R.S., vice- 

 president, in the chair. — A communication was read from Mr. 



