Oct. ii, 1888] 



NATURE 



56; 



of these numerous properties is adequately and most appropriately 

 represented by the Mongian equation. The question has been, 

 what fact in the history of the conic, if I may say so, is most 

 intimately associated with the vanishing of the Mongian ; end 

 that fact, I believe, is given in my interpretation. Wnether the 

 fact admits of an easy verification or not seems to me to be 

 wholly foreign to the question. 



Calcutta, July 27. ASUTOSH MUKHOFADHYAY. 



Upper and Lower Wind Currents over the 

 Torrid Zone. 



After my arrival in China in 1883, I made inquiries, among 

 persons who had kept meteorological registers, concerning the 

 direction from which clouds usually come here, but was told 

 that they came from all directions without any apparent order. 

 But the observations made during January 1884, printed in the 

 Weather Report published on February II, showed at once 

 clearly that the lower clouds came from the east, and that the 

 directions veered with increasing height, the highest clouds 

 coming from the west, as explained in the text of the Annual 

 Weather Report published on February 17, 1885. This might 

 have been expected in analogy with what obtains in cyclones, 

 as the trade-wind blows into the calm belt as if this were the 

 centre of a depression drawn out to extend round the whole 

 earth near the equator. 



The Hon. R. Abercromby, to whom my Reports were sent 

 without delay, convinced himself of the truth of those remarks 

 during a tour round the world, and addressed a letter to Nature 

 on the subject on October 26, 1885, but it is of importance that 

 the subject should be investigated at fixed observatories within 

 the tropics, where hardly enough attention has hitherto been 

 paid to the movements of clouds, to judge from what has hitherto 

 been published. 



In the Annual Weather Report for 1885, it is stated that, from 

 June to September inclusive, cirri come from two different direc- 

 tions — from about north-east while a typhoon is in existence 

 somewhere, their direction often backing from about east to 

 north while the centre of the typhoon is yet over 700 miles 

 away ; and from about west when there are no signs of a typhoon. 

 But cirri are rarely seen in summer except before typhoons, 

 through whose agency vapour is evidently carried up to the 

 higher regions of the atmosphere. It is, however, to be expected 

 that the existence of the southerly monsoon (caused by the low 

 barometer in the northern part of the Chinese Empire) during 

 the summer to some extent influences the movements of the 

 :louds. 



The following table exhibits from four years' observations 

 1884 to 1887 inclusive) the average directions from which the 

 wind comes at the Observatory, about 150 feet above M.S. L., 

 ind at the Peak about 1850 feet above M.S.L., as well as the 

 iverage directions from which the upper and lower clouds 

 :ome, but the difference between the latter is so great that 

 ntermediate directions will be missed : — 



Obs. 



Peak. 



.. E IO N 

 .. E 17 N 

 .. E 17 S 

 .. E 30 S 

 .. E.44 s 

 .. E67 S 

 .. E87 S 



S 

 .. E 1 N 

 .. E 8N 

 .. E 19 N 

 .. E 18 N 



Lower C. Upper C. 



... Eby S 

 ... EbyN 

 .. ESE 

 ... SE 

 ... SSE 

 ... S by E 

 ... S by E 



S 

 ... ESE 

 ... EbyN 

 ... ENE 

 ... EbyN 



W by S 

 W 



Why S 

 Why S 

 WNW 



NNW 

 NE 

 NE 

 NNE 

 Wby S 

 W by S 

 WSW 



Mean ... E 6 S ... E 22 S ... E3o°S ... W33°N 

 If an observer outside the earth were to determine the period 

 f this planet's rotation by observing spots formed by clouds, he 

 yould obtain different values according to the level of the respec- 

 ive cloud-layer, just as we obtain different values for the period 

 f rotation of Jupiter from observations of different classes of 

 pots. In the case of the earth, the observation of the highest 

 louds near the equator might possibly furnish a value of the 

 leriod too short by a tenth, and there is no doubt it would be 

 lifferent nearer the Poles. W. DoBERCK. 



Hong Kong Observatory, August II. 



The Natural History of the Roman Numerals. 



Some time ago I had the pleasure of reading in your journal 

 (vol. xxxvi. p. 555) an interesting article by Mr. Lymburn on 

 the above subject. In this the writer shows the probable evolu- 

 tion of the X ten > from the \J hand, and thence the broad 

 arrow, ^\. As the Scandinavians used this arrow sign, calling it 

 tiroxtyr, as an equivalent for "J" j n the Runes (see Taylor, " The 

 Alphabet," vol. ii., p. 18), it is therefore connected with the 

 Greek tau, the headless cross, the X °f tne Semitic languages. 

 I have no doubt that many of your readers take an interest in 

 anything bearing on this subject. This is my apology for calling 

 their attention to an article published in the last volume of 

 Transactions of the New Zealand Institute, 1 wherein I break 

 new ground by showing that the word tau was known in Poly- 

 nesia as a cross, as ten, and probably as meaning "writing." 



I have given, in the different dialects of New Zealand, Samoa, 

 Tonga, Hawaii, &c, the meanings of the word, and shown its 

 entry into other compound words. A brief precis runs as 

 follows : — 



Tatau (la-tau) is the Tahitian word which Cook brought to 

 us, and is better rendered by his spelling tattow than by our 

 English tattoo. In Maori, tatau means to count, to repeat one 

 by one ; but in Hawaiian it means to write, to make letters 

 upon, to print as upon tapa (native cloth) as in former times. 

 In this Hawaiian, tau means to dot, to fix the boundaries of a 

 land or country, to give publicity to a thing. In Tahitian, tatau 

 means not only to tattoo, but to count, number ; in Samoan, 

 tau is to count, and in Marquesan, tatau to reckon. In com- 

 position, too, it enters into many words, such as teacher, pupil, 

 genealogy, &c, and it seems impossible but that the tattooing 

 (at one time done in " three-marks " and arrow-heads) meant 

 some kind of character or script. 



As to the numeral "ten," I bring some interesting evidence 

 which I cannot condense. 



As to the figure of the cross being used as a sacred sign, 

 there are innumerable evidences to that effect in the Poly- 

 nesian islands ; notably that the Southern Cross is called in 

 Tahitian tau-ha ("four-cross"), and that the cross X was tne 

 taboo sign in front of Hawaiian temples. I have since learnt 

 that in the Solomon Islands the cross taboos anything to the 

 chief. 



Wellington, N.Z., August 5. Emv. Tregear. 



Indian Life Statistics. 



Though several weeks have now elapsed since Dr. Hyde 

 Clarke's inquiry about the effects of lucky and unlucky times 

 and seasons upon the Indian birth-rate was published (in 

 Nature of July 26, p. 297), none of your readers in England 

 who happen to be acquainted with India have come forward to 

 answer it. I therefore write to point out that, though the times 

 of Hindu marriages are to a very great extent controlled by 

 supposed lucky or unlucky days, months, or years, these have 

 nothing whatever to do with variations in the birth-rate, for the 

 usual age of marriage of girls is from eight to ten years, and 

 child-bearing at the earliest does not commence before twelve or 

 thirteen. 



With regard to the Holi and other religious festivals, I have 

 it on the authority of Mr. J. C. Nesfield, Inspector of Schools 

 in Oudh, who has made a life-long study of Hindu castes and 

 their customs, that, whatever the origin and primary significance 

 of the Holi may have been, it is not now connected in any 

 special manner with the multiplication of the species. The 

 religious ceremony to which the Hindu looks for the furtherance 

 of his desire for offspring is the Durga Pujah, or worship of the 

 consort of Shiva, which is the occasion of the annual family 

 reunion all over Bengal. In the Upper Provinces a totally 

 different festival is celebrated at the same time of the year— the 

 Ram Lila, a sort of dramatic performance or mystery-play, 

 commemorating the expedition of Rama to Ceylon for the re- 

 covery of his lost wife ; but Mr. Nesfield says that during the 

 Ram Lila some member of every family is specially set apart to 

 conduct a ceremonial worship of Kali, or Durga, ending with 

 the sacrifice of a male kid, and that the object of this ceremony 

 is to obtain the favour of Kali and her consort for the continu- 



1 Trans. N.Z. Inst., vol. xx., "Ancient Alphabets in Polynesia," by E 

 Tregear, F.R.G.S. (London : Triibner and Co.) 



