ON THE PERIODS AND NODES OF LOCHS EARN AND TREIG. 
§ 9. TrinopaL Prriop or Earn. 
T ¢ a 2(5 +a) a(5-a) | 43+) 4(3 — a) K(c, 1) 
5-700 | 23-1580 | 9-6737 36684 | —1:1684 31684 ~ 16684 + 81439 
5725 | 22°9559 | 9°6345 36586 | —1-1586 31586 - 16586 +8°7133 
5°750 22°7565 95930 3°6483 — 11483 31483 — 1:6483 + 9°3860 
ak é a 4(54+a’) 4(5 — a’) 4(3 +4’) 4(3 - a’) K(c’, 1) 
5-700 46930 4°4659 23665 1335 18665 — °3665 —4:7315 
Ome | 4:6521 | 44282 2°3570 1430 1:8570 = 3510 — 42585 
5750 | 46117 | 4-4099 2°3525 1475 1°8525 = 625 — 4:0900 
en (c) Diff. 
5700 — 2:1866 14400 
5725°| = “7466 10473 
5°750 + ‘3007 
T3=5°743' = 5-74 say. 
€,=22°8123; c',=4°6230. 
§ 10. Prriops By Du Boys’ Rute. 
The following table gives the details of the calculation of the Uninodal period 
by the Rule of Du Boys. The distances from the western end of the lake are denoted 
by «, the unit being 2 x 1760 =3520 feet; while the depth A is entered in feet. The 
19°84 
integration T, = 3520/,/(32°2) i dx//h proceeds along the line of greatest depth 
as indicated by the rule. 
[ TABLE. | 
