THE OCTAGON, NEWARK, OHIO. 1G 
1,054 feet. The widest divergence between the line of the survey and 
the circumference of the true circle is 4 feet. 
The aggregate length of the chords surveyed is 3,304 feet, while the 
circumference of the approximate circle is 3,311 feet; adding to the sum 
of the chords the additional length of the ares they subtend (0.1508 of 
a foot to each 100-foot chord), and we have a total of 3,309 feet. It is 
therefore evident that the inclosure approaches in form very nearly an 
absolute circle. 
The inference to be drawn from the fact that this and a few other in- 
closures noticed in this paper are so nearly true geometrical figures will 
be briefly discussed hereafter. 
““ OCTAGON,” NEWARK, OHIO. 
This inclosure, which is connected with the ‘‘Observatory Circle,” is 
shown in PI. IV. The southern portions, a to b, and b to ¢, remain 
almost uninjered, being still more or less covered by the original forest 
growth. The other lines of wall have been considerably worn by the 
plow, though they are still quite distinct, the height not being less at 
any point than 24 feet as shown by the figures of the field-notes. Ney- 
ertheless the wearing makes it difficult, often impossible, to determine 
with absolute certainty the middle line, though there is never any good 
reason why the survey should vary from the middle line of this or any 
other of these Ohio inclosures, distinctly traceable, more than 3 feet at 
most. 
The field-notes of the survey are as follows: Commencing at station 
No. 36 (so numbered in the survey of the Observatory Circle) at the point 
where the northern parallel joins the Octagon; thence to station 37, 
the point where the southern parallel joins the Octagon, thence to ) and 
round to the place of beginning. 
Survey of the Octagon. 
Width of Height of 
+3 , aD Yic > 
Station. Gearing. Distance. aah as 
Fl Feet Feet Feet 
BORLON ie Sa anieis aas\oc cinic.wicie nace othe Sie SGnSOeM aecses cos coe aac 82 
BOLO amcteaietenic(ses acajsimacie sa cee Un 49) 40 Mecmcieenccsievsscecac 580 40 to 43 DEM s LOtAa GF 
UG) Seen Bbce DE CAE TE ae ae aaa ING O45 Shy me ete onc ceeeoene 624.5 37 to 48 4.3 to4.2 
c tod Rielars Bo St Dal De SAM ae eae a are | 625 47 to 39 5.9 to 5.8 
(LATS), Cee SOBRE Coe ae een NG ZOmeCoE WL cee ae se beeen | 622 41 to 50 3.4 to 3.5 
Cam COM ree ee ce ese eats jess wicaind IN de SBN Wes oe cteiaeinonicceies =| 621 40 to 37 2.5 to 2.6 
jf iKD () opacs0 echo sonbooUSUCeeOeOnbee SGOELOPWicwececmee cee etooe. 613 47 to 43 8 to4 
JaetOM Drm oc/Scin soe ee aS cece cie sees SPO OM DAN cisacm oe web eome reas 621.5 45 to 47 4.3to4 
MP LOO Teer Reco eee Gok ee oneceee SS PUORAUPEY Acute este cinees tess 581.5 43 to 41 3,8 to 3.7 
The two numbers to each course in the width and height columns are 
two measurements of each wall near the ends in the direction of the 
survey. 
The stations indicated by letters are at the intersections of the lines 
of the walls: Station a is at the intersection of the lines h-36 and 37-b. 
LS6(——9 
