TRANSACTIONS OP THE SECTIONS. 



251 



1st. That the time of H. W. at all the points of obseiTation is practically the 

 same, allowance being made for the disturbing influence of weather; and the 

 same remark applies to L. W. 



2ud. That the level of H. W. at all points {actually within the Irish Sea) on 

 each coast, taken separately, is nearly identical ; and the same may be said of the 

 level of L. W. 



3rd. That the tidal range on the English coast is about double of that on the 

 Irish side. 



In explanation of these peculiarities it must be borne in mind that there are two 

 tides which set into the Irish Sea — the northern one round the north of Ireland, 

 and the southern one coming from the English Channel, the meeting of the two 

 being somewhat along a line drawn from Fleetwood across to Duudalk. 



Captain Beechey, R.N., who some j'ears back made considerable researches as to 

 the tides of the Irish Sea, described them under the name of " Stationary Tide," in 

 contradistinction to the " Progi-essive Tide," where the times of H. W. and of L. W. 

 at different points vary with the distance previously travelled by the tidal wave* 

 The result of the above-named simultaneous observations has been on this head to 

 confirm positively what Captain Beechey and others had supposed to be the case. 



The greater range of the tide on the English side, 30 feet at equinoctial springs 

 iis against 16 feet, may be accounted for by the shallow water of Morecambe and 

 Liverpool bays and along the English coast, where, under v\'ell-known tidal laws, 

 a considerable heaping up and a corresponding depression might be anticipated. 



At equinoctial springs the H. W. on the English side stands about 7 feet 

 above, and at L. W. about 7 feet beloiv that on the Irish coast ; while at equinoc- 

 tial neaps the excess on the English side, both at H. AV. and at L. W., is reduced 

 to little over one foot. 



Tides in the Irish Sea. 



Equinoctial Spring-Tide, April 8, 1875. 



L. W. 



Time. Height 



H. W. 



Time. 



Height 



L. W. 



Time. Height 



Remarks. 



Whitehaven 

 Barrow 



Fleetwood . . 

 Liverpool .. 

 Holyhead... 



Belfast 



Duudalk ... 



Dublin 



Kingstown 



h m 



6 45 A.M. 

 8 30 „ 



7 15 „ 

 6 45 „ 



5 la „ 



6 „ 



7 50 „ 

 6 „ 

 5 45 „ 



ft. in. 

 86 



84 



86 

 84 



89 8 



95 10 

 93 8 

 93 2 

 92 7 



h m 

 12 45 P..M. 

 1 .30 „ 

 12 45 „ 

 12 noon. 



11 30 A.M. 



12 15 P.M. 

 12 15 „ 

 12 45 „ 

 12 45 .. 



ft. in. 



113 



114 11 



115 8 

 113 11 

 108 2 



105 10 

 108 



106 2 

 105 1 



h m 

 7 15 P.M. 



9 „ 



7 45 „ 



7 15 „ 

 6 45 „ 



6 15 „ 



8 00 „ 

 6 15 „ 

 6 15 „ 



ft. in. 



86 

 83 7 



87 

 83 7 

 89 1 



94 10 

 93 10 

 92 8 

 91 11 



N.N.w.Btrong breeze, 

 N. light, 29-80. 

 N.E. gale, 29-50. 

 N.N.E. strong, 29-73. 

 N.E. strong. 



[30-20 

 N.E. strong breeze, 

 N.E. strong breeze, 

 N.E. strong. [30-0. 

 N.w. strong, 29-87. 



Equinoctial Neap-Tide, March 31, 1875. 



Whitehaven 

 Barrow . . . 

 Fleetwood 

 Liverpool... 

 Holyhead... 



12 15 p.M 

 12 15 

 12 noon. 

 11 45 a.m. 

 11 „ 



Belfast 12 noon. 



Dundalk ... 

 Dublin... 



Light. [30-60, 



N.w. fresh breeze, 

 N.w. calm, 30-50. 

 N.N.w. light, 30-60. 

 N.N.w.strong, 30-62, 



N.N.w. light, 30-60. 

 N.N.w. light, 30-65. 

 N. very light. 



Greenwich Time throughout (Dublin time being 25"' 21« behind Green-svich). 

 Datum of levels, 100 feet below English Ordnance. 



Assuming the Mean Sea-level to be uniform, Irish Ordnance =92 feet G^ inches 

 above Datum. 



