16 GEOMETRICAL EARTHWORKS OF OHIO, 
were taken. The field-notes are as follows, beginning at station 0 in 
the middle of the gateway leading to the octagon: 
Survey of Observatory Circle. 
Station. | Bearing. | Distance. | ayiauh of | Remarks. 
| | | 
- aC TER Sit Lee a | SS Ts eee Cpa oS aa 3 oe aa aay Bais, 3 
| ‘ \ Feet. Feet | 
OGtO Gales aS: a8 20 es 42 0 | Station 1 at junction of circle and south parallel. 
IeGOe Zest S120. 20eKer 2 100 | 36 | 
Ditoye3e5| Sealy Svs. 100 | oul 
Bit omaealeSs 16n00MBE 22 100 | 38 | 
APEO W5sel Se oy OUWes 100 | 38 | 
HCOmnGzals ep) OOAWE = 100 37 | 
Gato wisi. 27455 100 36 | Center of wall 2 feet east; that is, outward. 
TtO See Se8D, IIT AW.. | 100 34 | 
8to 9...) 8.48 40 W.. 100 Sees 
9 to 1U..| S. 58 16 W..| 100 3744] 
LO MOM ss) S693 NV 100 | 37 
11 to 12..} S. 82 00 W-..| 100 Sea 
LAOS ft ON OO LaeNv! | 100 41 
NS tO steel New O 20pNVe =| 100 SUA Ml 
14 to 15..| N.66 15 W..! 100 88(?), Width estimatcd, not measured. 
15\.torl6.22) NbosoG Wes 100 | 39 | 
16 to 17..| N.45 JO W.. TKO eee 9 hee eg | (‘“Observatory.’’) 
17 to 18 No SROB RW Esc 100 | 39° | 
18 to 19 N, 20. 29 W.. 100 | 42 | 
19 to 20 INES 22 Wes 100 | 43 | 
20 to 21 Nie Les4aWies 100 40 
21 to 22 N. 9 06E.. 100 39 
22 to 23 IN, 20 54, E:.- 100 38 
23 to 24 Neo eis 100 39 
24 to 25 IN 427 325H 2 100 40 
25 to 26 Iisa? Gio Dee 100 42 
26 to 27 INE 62) 43) Hy <2 100 40 
27 to 28 IN Ty O7eE 8 100 44 
28 to 29 N. &6 23E.. 100 40 
29 to 80 S827 ker. 100 44 | 
30 to 3l S. 72 04E.. 100 42 
31 to 32 S. 60 45 EF .. 100 45 
32 to 33..|S. 51 06E.. 100 45 | 
33 to 34..| S. 46 29E.. QO illsetee seater | Junction with north parallel wall. 
34 to 0.. S. 33 20E.. BD) |e iate olelsainin | Middle of gateway. 
34 to 36..) N. 52 04 E --| DDE ee weiten cee | North parallel. 
Loto 37.2) N. 51 53 .B 293 |..--22 2-22 es | South parallel. 
| 
Check Lines. 
| | 
0 to 11..| S. 18 28 W. B83¢| coe eee | 
Oto i S2 51 27a). LOST RSet eeeeee | 
Ontos CaiS 752,00 Wheel Pas teres =o ars ste “4 indicates the half-way point in the cireumfer- 
| | | ence. 
0 to 25..| N.85 10 W..|} RAY | reg Seog | 
1 tod SS 7 59's.) AUN es mae as ee 
LT *tor25. =| ONG 423. he MeO Nos cttecreceme| 
25 to 11..| S.28 03: E...} LODE yee Saris eee es 
In order to bring before the eye of the reader the approximate regu- 
larity of this circular work a figure, laid off to a scale, is introduced 
here (PI. If1). The solid black line of short chords marks the line of 
the survey along the top of the wall and the circular dotted line, the 
nearest approximate circle. Great care was taken in making the sur- 
vey, and the plat and calculation were found to confirm the accuracy 
claimed. : 
Measuring the various diameters the maximum is found to be 1,059 
feet and the minimum 1,050, the mean of which is 1,054.5 feet, but it is 
found by trial that the nearest approx'mate circle has a diameter of 
