222 BAROMETRICAL MEASUREMENT of 



Monticello, July 3d. 1796. 

 " Dear Sir, 



" 1 EXAMINED with great fatisfadion your barome- 

 trical eftimate of the heights of our rnountains, and with 

 the more as they corroborated conjectures on this fubjedl, 

 which 1 had made before. My efti mates had made 

 them a little higher than yours, (I fpeak of the Blue 

 Hidge). Meafuring with a very nice inftrument, the 

 angle fubtended vertically by the higheft mountain of the 

 Blue Ridge oppoiite to my own houfe, a diftance of about 

 1 8 miles fouth-v>'eilvvard, I made the height about 2000 

 feet, as well as I can remember, for I can no longer find 

 the notes I then made. You make the fouth fide of 

 the mountain near Rock-fifli Gap 1727 feet above 

 Wood's. You make the other fide of the mountain 768 

 feet. Mr. Thoma? Lewis deceafed, an accurate man, 

 with a good Quadrant made the north fide of the higheft 

 mountain oppofite to my houfe fomething more ( I think) 

 than 1 000 feet. i3ut the mountain eftimated by him and 

 myfelf is pi-obably higher than that next Rock-fifh Gap. 

 I do not remember from what principles I eftimated the 

 peaks of Otter at 4000 feet, but fome late obfervations 

 of Judge Tucker's coincided very nearly with my efti- 

 mate. Your meafures confirm another opinion of mine, 

 that the Blue Ridge on its fouth fide is the higheft in our 

 country, compared with its bafe. I think your obferva- 

 tions on thefe mountains well worthy of being publillied, 

 and I hope you will not fcruple to let them be communl- 



1 am, &c. 



(Signed) TH: JEFFERSON," 



When 



