310 Mr. H. H. Turner. On the Correction to the [Apr. 1, 



We then find for the set of latitudes and longitudes of evanescent 

 tide : — 



Nature of tide. 





1st hypothesis. 



2nd hypothesis. 





lat. X 



34° 39' N. 



35° 4' N. 





lat. Xj 

 long. l x 



1° 0' S. 

 55 50 E. 



1° O'S. 

 55 50 E. 





lat. X 2 

 long. l 2 



79° 54' N. 

 5 3 W. 



79° 56' N. 

 5 4 W. 



The other points of evanescence are of course easily derivable from 

 these, as shown in the first part of this paper. 



As a slightly closer approximation to truth, I have calculated these 

 integrals on another supposition. There are cases where lines satis- 

 fying the equations 



I— const, or A= const, 

 diverge somewhat widely from the actual coast line, but a line 



+ al+b\= const. 



(where a and b are small integers) can be found following it more 

 faithfully. An approximate coast line of the land on the earth is 

 defined in the following schedule, west longitudes and north latitudes 

 being considered positive. 



Limits of , Limits of 



longitude (Z). 



Equation. 



latitude (X). 



+ 20°to + 10° .. 



,. _\=z_40 



. .. +20° to +30° 







Z=10 



... +30 



„ +40 



+ io „ 



-23 .. 



_\ = z_50 



.. +40 



„ +73 



- 23 „ 



+ 120 .. 



X=73 











Z=120 



. .. +73 



„ +80 



+ 120 „ 



+ 20 .. 



\=80 











Z=20 



. .. +80 



„ +70 



+ 20 „ 



+ 50 .. 



. . — 3\=Z— 230 



.. +70 



„ +60 



+ 50 



+ 70 .. 



X=Z + 10 



. .. +60 



„ +80 



+ 70 „ 



+ 80 .. 



\=80 







+ 80 „ 



+ 50 .. 



X=l 



. .. +80 



„ +50 



+ 50 „ 



+ 90 .. 



-2\=Z-150 



.. +50 



„ +30 



+ 90 „ 



+ 100 



\=30 







+ 100 „ 



+ 80 .. 



X=Z-70 



.. +30 



„ +10 



+ 80 „ 



+ 70 .. 



\=10 







+ 70 „ 



+ 30 .. 



2X=Z-50 



.. +10 



„ -10 



+ 30 „ 



+ 78 



. . -X=Z-20 



-10 



„ -53 







1=73 



. . - 53 



„ -14 



