210 Miscellanies. 



province of Ceara, and over the village of Macao, at the entrance of the 

 Rio Assu ; it burst with a noise like thunder, and an immense quantity 

 of stones fell from it, in a line extending more than ten leagues. The 

 largest portion fell at the entrance of the river, and in various places they 

 pierced through several dwellings, and buried themselves several feet 

 deep in the sand. No human life was lost, but many oxen were killed, 

 and others severely hurt. The weight of those taken out of the sand 

 varied from one to eighty pounds. — The Athenceum, (London,) Dec. 16, 

 1837, p. 915. 



9. New Magneticdl discoveries. — We have been favored with an op- 

 portunity of inspecting some proof sheets of a work by Dr. Henry Hall 

 Sherwood, of New York, which will shortly be published, containing dis- 

 coveries in magnetism of a very extraordinary kind, and probably of great 

 importance. They include apparently unexceptionable demonstrations of 

 the latitude, longitude, rate of motion, and periodical revolution of the 

 magnetic poles, or " vortices" of magnetism, round the terrestrial poles ; 

 of the angles of the magnetic with the terrestrial meridians in every part 

 of the earth, at any given time ; together with a universal method of de- 

 termining latitude, longitude, and variation, under all possible circum- 

 stances, by the dipping needle alone. The perfect regularity of the lines 

 of no variation, and the value of their angles with the terrestrial axis in 

 every parallel of latitude, also seem to be demonstrated ; and this, in con- 

 nection with the relative position of the nodes of the magnetic with the 

 terrestrial equator, which is found with the utmost facility and precision, 

 forms the basis of calculations for determining the past, present, and fu- 

 ture variation of the compass needle, at any given place on the globe. 

 These calculations are tested by numerous observations made in various 

 countries, and the agreement is most strikingly exact in all the examples 

 adduced. 



One of the most interesting facts seemingly established in this work, is 

 that the magnetic poles revolve in the latitude of the arctic and ant-arc- 

 tic circles, or 23° 28' from the terrestrial poles ; and this coincidence is 

 ascribed to the solar origin of these magnetic vortices, and to the correla- 

 tive fact that the inclination of the earth's axis to the plane of the eclip- 

 tic is 23° 28'. In short, these discoveries, (here only partially and cur- 

 sorily mentioned,) sustained as they are by extremely simple calculations, 

 which evidently harmonize with all the recorded and original observa- 

 tions to which they have been applied, seem to warrant the expectation 

 that terrestrial magnetism, at least, will soon be rescued from its present 

 state of uncertainty and confusion, and elevated to a distinguished station 

 among the exact sciences. We await the publication of Dr. Sherwood's 

 work with an unusual degree of interest. — Communicated. 



