It appears, however, that in January the cyclones mostly travel across N.W.
The forms of these flocculi show that all sun-spots are vortical in nature, and are probably analogous to terrestrial cyclones or tornadoes.
From January to the middle of April, Mauritius, in common with the neighbouring islands and the surrounding ocean from 8° to 30° of southern latitude is subject to severe cyclones, accompanied by torrents of rain, which often cause great destruction to houses and plantations.
The south-east winds blow from the arid lands and carry rising temperatures across the state; and the winter anti-cyclones from the north-west carry low temperatures even to the southern border.
Nor are the laws of the anti-cyclones established.
The cyclones of the China Sea also occur in the hot months of the year, but they advance from north-east to south-west, though occasionally from east to west; they originate near the island of Formosa, and extend to about the 10th degree of N.
At the close of the dry season (end of February) cyclones from the N.E., usually accompanied by rain and thunder, burst over the land.
The laws and relations of the cyclones and anti-cyclones in Russia are not yet thoroughly understood.
In July they are pushed farther towards the N., and cross the Gulf of Bothnia, while another series of cyclones sweep across middle Russia, between 50° and 55° N.
The cyclones of the Bay of Bengal appear to originate over the Andaman and Nicobar islands, and are commonly propagated in a north-westward direction, striking the east coast of the Indian peninsula at various points, and then often advancing with an easterly tendency over the land, and passing with extreme violence across the delta of the Ganges.
While these are tracks frequently followed by the centres of barometric depressions, individual cyclones may and do cross the country in all directions, though very rarely indeed from east to west or from north to south.
The rainfall of England, being largely due to passing cyclones, can hardly be expected to show a very close relation to the physical features of the country, yet looked at in a general way the relation between prevailing winds and orographic structure is not obscure.
Meteorology.-It has always been held to be important to maintain a meteorological station on the Nicobars, for the purpose of supplementing the information obtained from the Andamans regarding cyclones in the Bay of Bengal.