DETERMINATION OF THE LONGITUDINAL SEICHES OF LAKE GENEVA. 635 
The extreme columns give the values of <~ n l n and k~ w I„, and are written with the 
values of n increasing up the column. The central portion of the table is supposed 
to be written on a separate piece of paper, so that it can slide up and down between 
the extreme columns. The values of k ~ n l' n are written, with n increasing down the 
w 
column, on the left-hand side of this central piece and in proximity to * ~ n l n ; 
w e 
similarly K ~ n l' n is written in proximity to ^ n l n - The middle column contains the 
values of /c _r T n (0, 2) as calculated from equation (2l), and the calculation is easily 
accomplished. Suppose the value of k‘ 6 I 6 (0, 2) be required ; then the central piece 
is moved down until the value n = 6 on it is opposite to n = 0 on the fixed sheet ; 
the terms of the various products of (19) are then contiguous, and the whole process 
can be rapidly performed on a calculating machine. The table given shows the 
arrangement for n= 6, and the central movable piece is enclosed by double lines. 
w 
K- n l n . 
n. 
n. 
K -»r n . 
K- n L(0, 2). 
K-n’,,. 
n. 
n. 
l 
[-00000004 
13 
13 
[•00000072" 
12 
12 
[-00001065' 
11 
11 
| -00013349 
10 
10 
■00140154 
9 
9 
•012096 
8 
8 
[-000000 
00660] 
•083874 
7 
7 
[-000000 
2578] 
•45376 
6 
0 
1-00000 
2-0000 
1 0000 
0 
6 
■000007 
9728 
1-8445 
5 
1 
1-84296 
18-5144 
9-4035 
i 
5 
■000186 
982 
5-3519 
4 
2 
■82141 
55-5745 
22-9944 
2 
4 
•003154 
1 
10-3037 
3 
3 
•163192 
84-9787 
25-8675 
3 
3 
•035646 
11-7405 
2 
4 
•018270 
79-3360 
16-5171 
4 
2 
•24352 
6-4240 
1 
5 
•0013098 
50-0488 
6-7554 
5 
1 
■84389 
1 0000 
0 
6 
■00006522 
22-7913 
1-9182 
6 
0 
1-00000 
7 
[-000002387] 
7-8521 
•40085 
7 
8 
[-000000067] 
2-1201 
•064320 
8 
9 
•46111 
•008187 
9 
10 
•08258 
•0008485] 
10 
11 
•012399 
•00007313 
11 
12 
•0015844 
"00000533’ 
12 
13 
•00017452 
’•00000034’ 
13 
9. Determination of the Periods. 
The solution of the period equation (20) is best effected by the use of Horner’s 
method. Let the notation J n = /c _ ”I 71 (0, 2) be used ; then we have to solve the 
equation 
J 0 -(kA)Ji + OcA) 2 J 2 - . . . +(-K\y\J r = 0, 
where J r is the last term considered. The accuracy of the solution will be affected 
