1850.1 On the Inland Storms of Tartary. 243 



writers, from the Chinese travellers and Marco Polo down to Humboldt 

 and Ehrmann, called Hurricanes, are undoubtedly most frequent, both 

 in the steppes and mountain chains of Tartary and Siberia. 



2. Now as connected both with Meteorology in general, and especi- 

 ally with the new science of the Law of Storms these land hurricanes 

 in all countries are of the highest interest, but in the countries above 

 named especially so, for the elevation, cold, and dryness of the air may 

 develope pheenomena of importance tending to disclose to us their 

 causes, or they may furnish us with confirmations or modifications of 

 the laws now supposed to govern storms. 



3. There are two great questions arising on the consideration of 

 them which are — 



A. Are they strait-lined currents of air, blowing from one point to 

 another ? or are they curves, and thus parts of rotatory storms ? and if 

 so which way do they turn ? and do they move onwards also ? 



B. Where are they formed? and how do they begin? at the sur- 

 face of the earth ? or in the atmosphere ? in a word, are they, like water- 

 spouts, descending storms ?* 



4. The first question is easily solved if we have only observations. 

 If the wind is a strait stream there will be no change in its direction while 

 blowing. If it is part of a circular storm moving onwards the wind 

 will veer according to fixed laws. If it be a circular storm, but station- 

 ary, as some are, it will seem to be a strait blowing wind at the place 

 of the observer, but if observations at a distance can be had, then it 

 will be seen that it was really blowing in a circle or curve. 



5. To explain this I send herewith a transparent horn-card on 

 which the winds are marked as they turn (against the hands (hours) 

 of a watch) in the northern hemisphere. In the southern hemisphere 

 they turn with the hours. 



6. This card may be supposed to represent any sized rotatory 

 storm, from a tornado of 100 yards to a storm of 1000 miles in dia- 

 meter. 



7. Now Humboldt and other travellers in Siberia speak of " horri- 

 ble tempests" of wind and rain from the plains of Tartary from the 



* There is some evidence, which will appear in a work I am now printing tend- 

 ing to shew that hurricanes at sea are descending storms ! hence the great import- 

 ance of this query. 



