TRANSACTIONS OF THE SECTIONS. 



21 



The position of the observer was not such as to sec at all well those coming from 

 Pisces till 12'' 4om. 



The night of August 11 and the morning of August 12 were cloudy, but the 

 positions and directions of flight of about a dozen shooting- stars were determined, 

 from which it appeared that the radiant-point was in Casseiopeia, but that it was 

 not so distinctly marked as on the previous night, and seemed to lie nearer to 

 y Casseiopeife *. 



On the Gales and Hurricanes of the Tnduin Ocean South of the Equator. 

 By CnAELES Meldetjm, M.A. 

 The author stated that by means of the log-books of vessels visiting the harbour of 

 Port Louis, the Meteorological Society of Mauritius, since its formation in 1851, had 

 been collecting meteorological statistics of the Indian Ocean in the fomi of a journal 

 showing the state of the winds, weather, and sea, on every day. The total number of 

 days' observations tabulated in chronological order down to the 31st of December, 

 18G5, is 170,000, and in some years the daily average is from 70 to 80 observations of 

 twenty-ibur hours each. Since 1853 a considerable number of S;s'noptic Charts (up- 

 wards of 500) have been constracted, and it is proposed to publish a series of such 

 charts, showing the state of the winds and weather over the Indian Ocean at noon 

 on each day for a period of one year. lu addition to these tabulated observations, 

 a mass of information has been collected regarding the gales which liave occun-ed 

 in the Indian Ocean, many of which have been described in the Society's Transac- 

 tions. As Secretai'v to the Society, the author had opportunities of studying these 

 gales, and being now in this country he begged permission to communicate some of 

 the results of his investigations. 



The gales and hurricanes of the Indian Ocean South of the Equator maybe thus 

 classified : — 1st, trade-wind gales, in which the wind veers little ; 2nd, the extras 

 tropical gales, between the parallels of 30° and 45° S., in which the wind generally 

 veers or shifts ; and 3rd, the tropical hurricanes, in which the wind always veers 

 or shifts. 



1. The trade-wind gales occur in all seasons, but chiefly in the winter months of 

 June, Jidy, and August, when the S. W. monsoon prevails north of the equator, 

 and the S.E. trade- wind acquires additional strength from the demand made upon 

 it to supply the monsoon, the two winds being apparently one system under the 



* A change in the position of the! radiant point of the August sliower on different nights 

 has long been suspected. See Professor Twining's remarks in the American Journal of 

 Science, 2nd series, vol. xxxii. p. 444, and vol. xxxvi. p. .305. It is to be regretted that the 

 cloudy state of the weather at St. Andrews prevented the settlement of tliis question ; 

 but probably some other observer has been more fortunate. 



