12 EIGHTH ANNUAL REPORT OF 



sun between the tropics, which rarifies the air, and causes it to ascend 

 into the higher regions ; producing below a current from the pole to- 

 wards the equator, and above a current in the opposite direction. The 

 resulting motions to and from the equator are not in a north and south 

 direction along the meridians, but are modified by the rotation of the 

 earth ; at the surface they deviate towards the west, and in the return 

 current above towards the east. If the point mentioned by Prof. Coffin 

 as the centre of the winds of the polar zone really exists, it is probably 

 that of maximum cold ; the air at this point would be condensed, and 

 flow from it in radial lines in every direction along the surface of the 

 earth. The paper is an important addition to meteorology, and has 

 cost the author years of labor. The publication of it has also been very 

 expensive, particularly on account of the maps and tables. 



3. Another memoir accepted for publication is, ' ; An Account of a 

 Tornado that passed near New Harmony, Indiana, April 30, 1852, by 

 John Chappelsmith." 



The eastern portion of the North American continent is almost every 

 year visited at different points by one or more tornadoes of frightful 

 energy, but of exceedingly circumscribed limits ; and it is almost an 

 opprobrium to the science of this country that more reliable data have 

 not been collected towards settling definitely the conditions of these re- 

 markable phenomena, and for ascertaining their cause. For this pur- 

 pose, however, mere verbal descriptions of the effects are alone insuffi- 

 cient ; there must be added to these accurate instrumental surveys, and, 

 if possible, the indications of the barometer, thermometer, and hygrom- 

 eter. The first accurate report of this kind was that by Professor A. D. 

 Bache, relative to a tornado which passed over the city of New Bruns- 

 wick, in New Jersey, in 1834. A similar survey was made by Pro- 

 fessor Eustis, of Harvard University, of the tornado of August 21, 1851, 

 which passed near Cambridge. 



We consider the present memoir as an exceedingly valuable addi- 

 tion to the stock of our knowledge on this subject. It gives not only 

 all the collateral phenomena as far as they could be obtained, but 

 presents a map of one square mile of the track on which are elabo- 

 rately plotted the relative position and bearings of the prostrated trees. 

 Some idea may be obtained of the enormous energy of this tornado 

 from the statement of the author, that " on a single square mile of 

 the track thousands of trees, many of them having a stem fifteen feet 

 in circumference, were prostrated by a force acting simultaneously in 

 opposite directions, and moving onward at the rate of a mile in a 

 minute." 



The author critically analyses the force at work, and arrives at the 

 conclusion that the proximate cause of the phenomenon is an inward, 

 upward, and onward moving column of air. Besides the map, the 

 memoir is accompanied by diagrams and sketches to illustrate the char- 

 acter and effects of the tornado. 



4. Another memoir is entitled " The Antiquities of Wisconsin," ex- 

 amined and surveyed by I. A. Lapham. 



In the Report for 1851, it was mentioned that Mr. Lapham, an expe- 

 rienced engineer, had undertaken, under the direction of the American 

 Antiquarian Society of Worcester, Massachusetts, to make explorations, 



