188 
IOWA ACADEMY OP SCIENCE 
I 
TABLE I. 
Length, 40.2 cms. Moment of inertia, 980 g. cm^ 
No. 
Amp. 
Period 
No. 
Amj). 
Period 
j No. 
Amp. 
Period 
0 
28.1 
5.149 
0 
74.5 
5.198 
1 0 
102.0 
5.300 
10 
26.6 
.147 
15 
62.2 
.192 
1 10 
83.0 
.287 
20 
25.1 
.145 
25 
55 . 0 
.186 
1 30 
52.8 
.262 
30 
23.6 
.144 
35 
49.0 
• .183 
i 40 
42.6 
.250 
40 
22.4 
1 .142 
50 
41.3 
.178 
50 
34.2 
.238 
50 
21.2 
i .141 
70 
33.3 
.171 
60 
28.3 
.228 
70 
19.2 
! .139 
• 90 ^ 
27.3 
.165 
70 
23.8 
.218 
90 
17.4 
.138 
120 
21.3 
.158 
80 
19.8 
..208 
no 
16.2 
.136 
150 
17.0 
.153 
90 
16.8 
.200 
130 
15.0 
.135 
180> 
13.5 
.149 
no 
12.1 
.188 
150 
14.0 
.135 
200 
12.0 
.147 
130 
10.0 . 
.180 
170 
13.2 
.134 
210 
11.3 
.145 
140 
8.9 
.175 
190 
12.4 
.133 
230 
10.3 
.143 
160 
7.3 
.167 
210 
11.8 ■ 
.133 
240 
9.8 
.143 
180 
6.2 
.161 
230 
.132 
250 
9.4 
.142 
200 ■ 
5.3 
.157 
300 
”9^2 
.131 
300 
7.6 
.140 
230 
4.4 
.155 
350 
8.2 
.130 
350 
6.3 
.138 
250 
3.9 
.i54 
400 
7.4 
.129 
•400 
5.4 
.135 
350 
2.6 
.150 
450 
6.9 
.129 
450 
4.7 
.133 
400 
2.3 
.148 
973 
3.31 
1 
.128 
874 
2.35 
.133 
450 
2.1 
.147 
0 
1 
190.0 
5.508 
1 
0 
308.0 
5.820 
0 
738.0 
5.986 
10 
135.0 
.498 
5 
249.0 
• .813 
5 
619.0 
.986 
20 
91.0 
.468 
10 
195.0 
.795 ' 
10 
517.0 
.986 
30 
58.2 
.427 
15 
150.0 
.771 
15 
426.0 • 
.986 
40 
36.3 
.364 
20 
109.0 
.730 
20 
344.0 
.985 
50 
24.8 
! .312 
25 
78.0 
.676 
25 
270.0 
.972 
60 
17.3 
.274 
30 
53.0 
.601 
30 
206.0 
.946 
70 
13.3 
j .249 
35 
37.0 
.520 
35 
150.0 
.905 
90 ■ 
8.6 
.226 
40 
27.0 
.435 
■ 40 
104.0 
.847 
no 
6.0 
!■ .212 • 
45 
20.0 
.390 
50 
46.0 
.‘673 
130 
4.6 
; .201 
50 
16.0 
.365 
60 
22.0 
.515 
150 
3.7 
i .193 
60 
10.0 
.326 
65 
17.0 
.465 
160 
3.4 
191 
70 
7.0 
.300 
70 
13.0 
.425 
170 
3.1 
! .189 
80 
6.0 
.271 
80 
9.0 
.383 
180 
2.8 
i .187 
90 
4.80 
.250 
90 
6.1 
.362 
200 
2.5 
.184 
100 
4.1 
.234 
100 
5.0 
.340 
220 
2.2 
.182 
120 
'3.08 
.227 
120 
3.7 
.300 
240 
2.1 
.180 
140 
2.4 
.222 
140 
2.75 
.280 
250 
2.0 
.178 
160 
2.09 
.216 
160 
2.1 
.265 
300 
1.6 
.172 
170 
1.98 
.214 
210 
1.4 
.259 
