120 REPORT— 1867. 



great revolving storm, the centre of wMeh passed on the east side of the 

 island, at a nearest distance of 129 miles. 



Another gale took place between the 22ud and 27th of February. The ba- 

 rometer fell to 29-660. On this occasion the wind veered from S.E. to E., 

 N., and N.W., and had a maximum force of 9 lbs. The rainfall was 7-455 

 inches. This was another revolving storm, which, as shown by the veering 

 of the wind, passed the island on its north and west sides. The nearest 

 distance of the centre was 220 miles. 



The nest gale occurred between the 18th and 27th of March. The lowest 

 reading of the barometer was 29-464. The wind veered from S.E. to S., 

 S.W., W., and N.W., and exerted a maximum force of 13 lbs. on the square 

 foot. The rainfall was 4-075 inches. This was another revolving storm, 

 which, Kke the fii'st, passed on the east and south sides of the island. The 

 nearest distance of the centre was 170 miles. 



A fourth gale took jJace on the 21st of June, with the barometer standing 

 at 30-252 to 30-314. The wind was from south to S.S.E., and blew with a 

 maximum force of 18 lbs. There was no rain. This was not a revolving 

 storm, but one of the -winter gales, in which the wind veers very little, and 

 which are apparently the immediate effect of the trade-wind being put in 

 violent motion by the same causes that produce the S.W. monsoon of the 

 Bay of Bengal, which the S.E. trade-wind supplies with air. 



1861. — In Eebruaiy 1861 a hurricane occurred which lasted six days, 

 namely, from the 11th to the 17th. It was a revolving one. For three 

 days it remained nearly stationary, its centre bearing about 110 miles N.N.E. 

 of the Observatory. The wind blew in fearful gusts, attended -with torrents 

 of rain, from S.S.E. to E.S.E., for &\e days, and then veered to E., N.E., 

 N.W., andW. The barometer fell to 29-009 on the mornrag of the 16th, 

 the centre of the storm at that time bearing N.W. 50 miles, which was its 

 nearest distance. In the night of the 13th, the vane of Osier's anemometer 

 was blown away, the pressure being then about 30 lbs. ; the greatest pres- 

 sure afterwards cannot have been less than 40 lbs. From 9| a.m. on the 

 11th to 9| A.M. on the 17th, 44-730 inches of rain fell at the Observatory, 

 and at Yacoas, 13 miles to the southward, at an elevation of 1200 feet, 99 

 inches feU in the same time. The centre of the storm passed between 

 Mauritius and the neighbouring island of Reunion. 



Another severe hurricane took place from the 7th to the 16th of February, 

 in the space between 10° and 20° S. and 76° and 84° E. ; so that two hurri- 

 canes raged at the same time. 



A third severe hm-ricanc, but of much shorter duration, took place on the 

 2nd and 3rd of March. The wind veered from S.E. to S., S.W., and W., 

 and blew with a maximum force of about 36 lbs. The barometer fell to 

 29-282, the centre of the storm, which was a rotatory one, being then 140 

 miles E.S.E. of the Observatory. This hurricane passed on the east side of 

 the island. 



1862. — This was comparatively a tranquil year at Mauritius, only two gales 

 having occurred, neither of which was violent. The first took place on the 

 26th of February. The wind was from S.S.E. to E., and attained a maximum 

 force of 12-50 lbs. The barometer fell to 29-888. The weather at Port 

 Louis, except on the 26th, when it was overcast and showery, was fine ; but 

 away to the north-eastward, between 8° to 16° S. and 60° to 110° E., the 

 S.E. trade-wind and IS^.W. monsoon wore in stormy collision, and two severe 

 hurricanes were encountered in that locality, both raging on the same days. 



The next gale in the course of this year was experienced on the 1st and 



