166 PHILOSOPHY OF STORMS. 



west or south west ; and all the tornadoes which have been 

 observed by scientific men, travel from a little south of west 

 in that latitude. It may be added that of eleven land spouts 

 or tornadoes, which passed through New York, Pennsylva- 

 nia, and New Jersey, every one had the trees thrown down 

 with their tops inwards and forwards, not one tree being dis- 

 covered with its top lying out at the side. Thus proving, 

 beyond a doubt, that in land spouts the wind blows towards 

 the centre" of the spout. How is it at sea ? In several great 

 storms in the United States, of several hundred miles in di- 

 ameter, which have been investigated with great care by the 

 joint committee of the American Philosophical Society, and 

 the Franklin Institute of the State of Pennsylvania, the 

 wind has been discovered to blow for many days in succes- 

 sion towards the storm, on all sides round the storm. Is 

 this the case at sea ? 



If, as is probable, opportunities be presented of observing 

 volcanoes, let it be seen whether they ever produce rains 

 immediately after they break out ; first, in the neighborhood 

 of the volcano, and afterwards, extending to greater dis- 

 tances. Are these rains ever attended with violent torna- 

 does, and sometimes with hail ? Are the smoke and ashes 

 carried in all directions above to a great distance, or are 

 they carried further on one side than on another ? 



The fluctuations of the barometer in connection with 

 storms, will of course be noted. Much "knowledge is yet 

 wanted to enable- us to read the indications of this valuable 

 instrument ; observe whether it ever rises before the de- 

 pression which always takes place in great storms, and at 

 the moment of the calm which may probably be experienced 

 in the middle of the storm, mark the greatest depression. 



131. The four diurnal fluctuations of the barometer should 

 also claim particular notice. Very laborious and highly in- 

 teresting observations on these fluctuations have lately been 

 made in India, which are recommended to the attention of 

 the meteorologist. 



