360 



APPENDIX. 



Xo. XIX. 



Semidiurnal maximum Spring range and minimum Neap 

 range. 



In the accompanying diagram, I have plotted the fourth 

 and fifth columns of the preceding table, as follows : 



a a is the range of Spring tides following the new moon. 



of of is the range of Spring tides following the full moon. 



A A is the mean of the two foregoing curves. 



b b is the range of Neap tides following the moon's first 

 quarter. 



b' b' is the range of Neap tides following the moon's 

 third quarter. 



B B is the mean of the two foregoing curves. 



