American Philosophical Society. 535 



quently interrupted. The observations for the months of July and 

 August 1838 were, however, represented by comparative diagrams, 

 which were exhibited to the Society. From this comparison it ap- 

 peared, that the form of the hne representing the course of the wind 

 as registered by the instrument at the two places is nearly identical, 

 thus proving the consistency of different instruments of this con- 

 struction with one another. The scale of the two instruments ap- 

 peared to be different, nearly in the ratio of 2 to 1 , but no direct 

 comparison of the scales had been attempted. It was stated also, 

 that, during 1837 and 1838, observations had been made with Mr. 

 Whewell's Anemometer at Edinburgh by Mr. Rankine, and ex- 

 pressed in a diagram (according to the method recommended by 

 Mr. Whewell) in the 14th volume of the Edinburgh Transactions. 

 Observations with this instrument have also been made at Plymouth, 

 and reduced by Mr. Southwood (of St. Peter's College), by whom 

 also the diagrams for Cambridge were constructed. Mr. Whewell 

 stated, in conclusion, that there is every reason to believe, from the 

 results hitherto obtained, that if any person with sufficient leisure 

 were to take up this subject, it will reward him by leading to the 

 knowledge of important meteorological facts and laws. 



AMERICAN PHILOSOPHICAL SOCIETY. 



July 20, 1838. — The Committee appointed on the communication 

 of Dr. John Locke of Cincinnati, read at the last meeting, [consisting 

 of Messrs. Peter S. Duponceau, R. M. Patterson, and J. Saxton,] 

 made the following report, which was adopted. 



" The Committee to whom was referred the communication of 

 Professor John Locke, of Cincinnati, report, that it gives the details 

 of a series of experiments, made for the purpose of determining the 

 magnetic intensity and dip for certain positions in Ohio. For these 

 experiments he had furnished himself in London with the best ap- 

 paratus, and had vibrated there two needles of the form recom- 

 mended by Hansteen, and one in the form of a small flat bar. Five 

 months afterwards, namely, on the 17th of January, 1838, he again 

 vibrated these needles at Cincinnati, and found the ratio of hori- 

 zontal intensity at the former place to that at the latter, as follows : 

 by needle, No. 1, as 1 to MG24 ; by needle, No. 2, as M639 ; by 

 No. 3, as 1 to 1-2037. Of these results the author prefers the last ; 

 inasmuch as the magnetism of needles is hable to decrease, but not 

 to increase. 



" On the 20th of August, 1837, he made experiments with his 

 dipping needle, to determine the dip at Westbourn Green, near 

 London, the mean of which gives 69^ 23'-3. 



" On the 26th of November, 1837, the mean of a series of ex- 

 periments made at Cincinnati, in lat. 39° 6' N., and long. 84° 27' 

 W., gave the dip = 70° 45'-7.5. 



'• At Dayton, Ohio, in lat. 39° 44' N., and long. 84M1' W., the 

 dii) was found to be 71" 22'-75 on the 26th of March 1838. 



•• At Springfield, Ohio, in lat. 39" 53' N., and long. 83" 46' W.. 

 the dip was found on tlic 29th of March 1838. to be 71" 27'-375. 



