Identification of the British Inch as the Unit of Measure. 147 



certainly one of the most noteworthy is to be found on Plate 23, 

 p. d-iy. This exception embraces "The Dunlap Works," Ross 

 County, Ohio. They lay within one mile of the Cedar Bank 

 Works, and within two miles of the Hopeton Works, already 

 cited ; consequently they can be taken as partaking of the nature 

 of, and as a connected branch of development of the works of the 

 Scioto Valley, the Newark Works, the Marietta Works, and so on. 

 They are situated on the right bank of the Scioto river, six miles 

 above Chillicothe. The copy of the survey is given as Figure VII. 



Upon examination of the original plan the construction is sin- 

 gular, though not noticed by the surveyors. A trial test line a b, 

 parallel to the long way, is the diagonal of the irregular square, 

 and extended locates the corner of the rectangular out-work, whose 

 long side is parallel to one side of the square. Constructing the 

 rectangular out-work, the extension c d of its short side passes 

 through the center point of, and as to a part, becomes the diam- 

 eter line of the circle attached to the square. Thus the measuring 

 numbers of these various parts become related to each other by 

 geometrical construction. 



On the long way of 1130 feet it will be observed the survey- 

 ors have shown a line 100 feet long, as its height (of breadth) 

 vertical to the horizon. The rectangular out-work is 280 feet long 

 bv 80 feet broad, and its area is 22400 feet, the half of which is 



