288 On the Magnetic Properties of' the Rock, <^-c. 



minent are laid down on the plan. That marked with a fleur- 

 de-lis denotes the true north, and Obs". the direction of the Ob- 

 servatory. 



Table of Bearings of the Observatory. 



From an examination of the table, it will appear that the 

 greatest deviations take place at the points A, E, F, G, H, and 

 M. In this case, a reference may be made to the plan for the 

 purpose of giving a more distinct conception. 



The more remarkable anomalies, it appears, take place at the 

 points G and H, where the needle is almost completely reversed. 

 This shows that the portion of the rock under the compass 

 there possesses the property of a natural magnet, having its 

 poles nearly in the direction of the meridian, — the north pole 

 being towards the north, and the south pole towards the south, 

 since, by a well known law in magnetism, the opposite poles at- 

 tract each other, while the same poles repel one another. 



I have been more anxious to announce this fact, for the pur- 

 pose of calling the attention of geologists and others to it, than 

 to trace all its consequences, which must be left to future obser- 

 vation and research. 



*3it* On the 27th these experiments were repeated, and the 

 results confirmed, by M. E. G., a friend of the author. 



O71 the Proximate Causes of certain Winds and Storms. By 

 Professor E. Mitchell, University of North Carolina. 

 (Continued from page 179.) 



Of the Prevalent Movement of the Air in Winds and Storms. 



XT may be of use, before proceeding to account for the general 

 facts stated in the commencement of this paper, to turn our 

 attentioft to the general theory of winds, and the causes by 



