ON THE HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 4] 
Hence we must complete the row numbered 369. 
The R Series. 
Here ny=2y—n=2 x 15°-0205343 per hour. 
To minimise the effect of M,, 
No=2y —2e, 
Ny —Ny=2o —n=1°-0569644 per hour. 
1:0569644q=15°02053487. 
If r=25, q=355'28, and r=26, q=369-49. 
Hence we should either complete the row numbered 355 or that 
numbered 369. 
The 2MS Series. 
Here n= 2y—40 + 2n=2 x 13°°9841042 per hour. 
To minimise the effect of M,, 
No=2y— 2a, 
N, —Ng= —2(¢—n) = —1°'0158958 per hour. 
1:0158958g=13'9841042r. 
If r=24, g=380°37, and r=25, q=344'13. 
Hence we should either complete the row numbered 330 or that 
numbered 344, 
The 25M Series. 
Here N= 2y +20 —4n=2 x 15°°5079479 per hour. 
To minimise the effect of M,, 
Ny=2y —2o, 
Ny —Ng=4(a—n)=2°'0317916 per hour. 
2°0317916q=15-5079479r. 
If r=48, g=366°37. 
Hence we should complete the row numbered 366. 
The O Series. 
Here _ 1 =y —20=13°'9430356 per hour. 
To minimise the effect of K,, 
nNea=Y> 
2, —Ng= — 2a= —1°:0980530 per hour. 
1:0980330q=13°9430356r. 
if r=27, g=342°85. 
Hence we should complete the row numbered 343, cutting off the 
last three entries in the present forms. 
The P Series. 
Here nN, =y—2n=14°-9589314 per hour. 
It is open to question whether it is best to minimise the effect of 
K, or of O. 
