293 Variation and Dip of the Magnetic Needle. 



1832, 8° 25'; in 1834, 8° 50' W. The town lines north of 

 Onion river, Vermont, were run from 1784 to 1787 at N. 36° E. 

 About twenty years after, the same Hnes were N. 35° E., and the 

 last summer I tried and found the same lines N. 37° 50' E/ ' 



Prof. Farrar, of Harvard University, Massachusetts, writes thus : 

 "I endeavored in 1810 to ascertain the variation of the needle in 

 this place as accurately as I could. I made it 7° 30' W., at 10 

 o'clock, A. M. I have now (July, 1835) observed the needle with 

 great care almost every day for the last two months. The mean 

 of my ten o'clock observations gives 8° 51' W." 



Prof. Hitchcock of Amherst College, determined the variation 

 of the needle at Deerfield, Mass., in 1811, to be 5° 28' W. 



Mr. George Gillet, Surveyor for the state of Connecticut, de- 

 termined the variation of the needle at Hebron, Conn., to be in. 

 1805, 4° 50' W., and in 1835, 6° 10' W. 



Prof R. M. Patterson of Virginia University, lat. 38° 2' N., long. 

 78° 31' W., states that the nfiedle there, in 1835, had no sensible 

 declination. 



Mr. John Bethune, surveyor for the state of Georgia, gives the 

 variation at Milledgeville, lat. 33° 7' in 1805 at 5° 30' E., and in 

 1835 at 4° 40' E. 



Prof James Hamilton of Nashville University, Tennessee, 

 states the variation at that place to have been 7° 7' E. in 1835, 

 and adds, " I have lost the record of observations made several 

 times since the year 1827, and have forgotten what the variation 

 has been heretofore. The city surveyor however assures me that 

 in the year 1829 I gave him the variation 6° 50' E., and that he 

 has it on record. " 



Mr. James H. Weakly, surveyor for the state of Alabama, writes 

 from Florence ; " The variation of the needle is here 6° 28' E. Dur- 

 ing the years 1817, 8, 9, it was about 6° 35' E. About the year 

 1809, it was 8° 10' E. at Mobile ; at this time it is about 7° 12' 

 E. During the survey of the Creek Territory in 1832, which 

 lies on the eastern border of the state, it was found in some places 

 in the northern part of the survey 5° 25' E., and in the southern 

 part about 6° 30' E." 



In addition to the preceding, the Hon. Timothy Pitkin, of Con- 

 necticut, has kindly put into my hands a collection of documents 

 containing many very valuable observations. In 1810, a represen- 

 tation on the subject of the variation of the magnetic needle was 



