98 



MR. AIRY ON THE LAWS OF THE TIDES 



For the investigation of the effect of the moon's declination^ the same process in 

 all respects was used as in Section V., pages 32 and 33, and the following are the re- 

 sults : — 



Station. 



Mean height 

 with small 

 dechnation. 



Mean height 

 with large 

 declination. 



Excess of mean 

 height with 



large declination 

 above mean 

 height with 



small declination. 



Mean height 



with decreasing 



declination. 



Mean height 



with increasing 



declination. 



Excess of mean 

 height with de- 

 creasing dechna- 

 tion above mean 

 height ^vith in- 

 creasing dechna- 

 tion. 



Kilbaha 



Kilrush 



Foynes Island. . . 



Limerick 



Casleh Bay 



Galway 



Old Head 



Mullaghmore . . . 



Buncrana 



Port Rush 



Carrowkeel 



Bally castle 



Glenarm 



Donaghadee . . . 



Ardglass 



Clogher Head . 



Kingstown 



Courtown 



Dunmore East . 



New Ross 



Passage West . . . 

 Castle Townsend, 



ft. 



15-61 



16-40 



17-15 



17-68 



17-94 



17-54 



17-71 



18-07 



17-37 



17-68 



17-97 



17-47 



17-68 



17-79 



17-69 



17-21 



17-41 



16-60 



15-80 



16-74 



15-70 



15-42 



ft. 



15-66 



16-46 



17-18 



17-57 



18-00 



17-58 



17-81 



18-15 



17-42 



17-70 



18-12 



17-59 



17-76 



17-85 



17-73 



17-29 



17-50 



16-67 



15-88 



16-68 



15-77 



15-47 



ft. 

 -fO-05 

 -fO-06 

 -fO-03 

 -0-11 

 .fO-06 

 + 0-04 

 -fO-10 

 + 0-08 

 + 0-05 

 -f 0-02 

 -fO-15 

 -f 0-12 

 + 0-08 

 -J- 0-06 

 -f-0-04 

 -fO-08 

 + 0-09 

 + 0-07 

 -j-0-08 

 -0-06 

 + 0-07 

 + 0-05 



ft. 



15-68 



16-52 



17-24 



17-81 



18-03 



17-62 



17-91 



18-22 



17-53 



17-88 



18-18 



17-64 



17-87 



17-93 



17-82 



17-29 



17-53 



16-70 



15-90 



16-85 



15-77 



15-46 



ft. 



15-59 



16-34 



17-07 



17-43 



17-91 



17-49 



17-69 



18-06 



17-31 



17-59 



17-94 



17-39 



17-66 



17-77 



17-64 



17-20 



17-42 



16-63 



15-79 



16-61 



15-70 



15-44 



ft. 

 + 0-09 

 + 0-18 



+ 0-17 



+ 0-38 

 + 0-12 

 + 0-13 

 + 0-22 

 + 0-16 

 + 0-22 

 + 0-29 

 + 0-24 

 + 0-25 

 + 0-21 

 + 0-16 

 + 0-18 

 + 0-09 

 + 0-11 

 + 0-07 

 + 0-11 

 + 0-24 

 + 0-07 

 + 0-02 



Upon comparing the results of this Table with those of the Table on page 96, the 

 remarks made in page 33 must, I think, be considered to be insufficiently founded. 

 The excess found by classifying according to the magnitude of the tide is here de- 

 cidedly greater than that found by classifying according to the moon's declination. 

 In the river tides (from Kilbaha to Limerick, and from Dunmore East to New Ross) 

 the excess classified by the magnitude of tide proceeds more regularly than that 

 classified by moon's declination. I think also that the change for the stations on the 

 narrow channel from Port Rush to Donaghadee inclines us to the supposition that 

 the whole is due rather to the variation of magnitude than to the variation of declina- 

 tion. The change of declination, being very slow, would probably produce the same 

 sensible change in the mean level of the deep (though contracted) sea of the North 

 Channel as in that of the Atlantic Ocean : though everything which depended in any 

 way upon the tides might be very different. Perhaps however the change for these 

 stations is not sufficiently decided to give great force to this argument. On the 

 whole, I regard the origin of this inequality as yet subject to some doubt. 



The values of Aq at any one station differ, sometimes rapidly, from day to day. In 

 order to examine these, I have subtracted from every value of Aq at each place the 



