PLAN OF AN ANCIENT FORTIFICATION AT MARIETTA, OHIO. 27 



Commonwealth of Massachusetts ; Boston, March the 21th 1787. 



Sir 



I beg Leave to communicate to joiir Excellency and the Academy a Plan of some 

 antient Ruins in the Western Territory — they were discovered in the last year by an 

 American Garrison at Fort Harmar, and have their Antiquity incontestibly evinced. 



Altho' there are not wanting Proofs that the western Country was once populous, 

 and of science, yet I believe that no Other works have been investigated which in- 

 dicate so much the Appearance of military Knowledge — and I cannot but observe 

 that here the Art of Defence seems to have been well understood. 



At Grave Rivulet (which Receives its Name from a large artificial Mount of Earth 

 about Seventy Miles from the Ruins) are very extensive Fortifications, consisting of 

 large elliptical Forts, and circular Redoubts — they bear similar Testimonies of An- 

 tiquity with those in the annexed Plan, but are of inferior Style and Aspect. The 

 Mount of Earth is an Object of great Curiosity to Travellers, and was once I imagine 

 nearly in Form of a Cone, but at present the Top is irregularly sunken in, and of sixty 

 feet Diameter. Human Bones are dug from every part of it, and to the very summit 

 is a luxuriant Growth of fine tall Oaks. 



I had no Instrument with me for taking the Altitude of this Grave, but I meas- 

 ured the Circumference, which was equal to seven hundred and eighty three Feet, 

 and over the Summit from opposite Parts of the Base two hundred and ninety — 

 which, by a Geometrical Construction of the Figure, gives nearly seventy Feet for 

 its Height. 



With great Respect 



I have the Honor to be 



your Excellency's 



most obedient 



most devoted Servant 



W. SARGENT. 

 His Excellency GOVERNOR BOWDOIN, 



President of the Academy of Arts and Sciences. 



