ON THE COASTS OF IRELAND, 



these levellings. The first result, or that by the shortest line, was adopted in the 

 reduction of the tide-observations. 



Depression of the Bench-mark at Mead's Quay, Limerick, below the bolt at Buck- 

 ingham Lock, Dublin. 



Line along which the levels were carried. 



From Dublin by Monasterevan and Borris-in-Ossory ; the difference 

 of level from Borris-in-Ossory to Limerick being the mean of 

 those found by Nenagh and by Holycross 



From Dublin by Cork, Mallow, and Tralee ; the difference of level 

 from Dublin to Cork being the mean of those found by Monas- 

 terevan, Borris-in-Ossory, Cahir and Mallow, and by New Ross, 

 Waterford and Dungarvan 



From Dublin by Gorey, New Ross, Waterford, Mallow and Tralee ; 

 the difference of level from Waterford to Mallow being the mean 

 of those by Cahir and by Cork 



From Dublin by Ballinasloe, Oranmore, Liscanor and Kilrush .... 



Approxi- 

 mate lengtl 

 in miles. 



127 



317 



312 

 233 



Depression 



by forward 



levelling. 



feet. 



0-629 



0-032 



0-249 

 0-899 



Depression 

 by back 

 levelling. 



feet. 



Mean of 

 results for- 

 ward and 

 back. 



feet. 



0-651 



0-744 



— 0-350 



0-889 



0-640 



0-388 



-0-050 

 0-894 



In order to give the means of verifying the principal results of the tide-observations 

 at any future time, I subjoin a statement of the positions of the bench-marks at the 

 different tide stations, and of their difference in elevation from the bolt at Bucking- 

 ham Lock, Dublifi. 



Tidal Station. 



Description of the permanent mark. 



Kilbaha 



Kilrush 



Foynes Island . 



Limerick 



Casleh Bay . . . 



Galway 



Old Head . . . 

 Mullaghmore . 

 Buncrana ... 

 Port Rush . . . 

 Carrowkeel. . . 

 Ballycastle . . . 



Glenarm , 



Donaghadee . , 



Ardglass , 



Clogher Head. 

 Kingstown .... 

 Courtown . . . , 



Dunmore East 

 New Ross .... 

 Passage West. . 



Castle Townsend 



Top of copper bolt driven vertically into one of the facing-stones of the pier . . 

 Top of copper bolt driven vertically into one of the facing-stones of the pier . . 



Top of copper bolt driven vertically into the solid rock 



Copper bolt driven horizontally into one of the facing-stones at Russell's Quay 

 Top of copper bolt driven vertically into the solid rock, close to the Coast-Guard 



Watch House. 



Copper bolt driven horizontally into one of the facing-stones at the entrance to 



the New Dock 



Copper bolt driven vertically into one of the facing-stones of the quay 



Copper bolt driven vertically into one of the facing-stones of the south pier. . 

 Copper bolt driven horizontally into the scarpwall of Ned's Point Battery . . 



Copper bolt driven vertically into one of the facing-stones of the quay 



Copper bolt in the wall of the Police barrack 



Copper bolt driven vertically into one of the stones of the quay 



Copper bolt driven into the solid rock on which the pier is built 



Copper bolt driven vertically into one of the facing-stones of the quay 



Copper bolt driven vertically into one of the facing-stones of the pier, near the steps 



Mark on one of the facing-stones of the pier 



Top of copper bolt driven vertically into one of the facing-stones of the pier 

 Top of copper bolt driven vertically into one of the facing-stones of the entrance 



to the harbour , 



Top of copper bolt driven vertically into one of the facing-stones of the pier , 



Mark in one of the facing-stones of the quay 



Top of copper bolt driven vertically into one of the coping-stones at the edge of 



the pier 



Top of iron bolt driven vertically into the rock in which the Coast-Guard signal 



staff is secured 



Elevation of 

 the mark 

 above the 

 bolt at Buck- 

 ingham Lock 



feet. 



— 2-814 



— 1-974 



— 2-920 



— 0-850 



+ 0-004 



— 3-000 



— 0-870 



— 1-749 

 -j- 18-203 



— 6-900 

 -1-24-820 



— 2-2d8 



— 9-388 

 -f. 0-321 

 + 0-838 

 -I- 2-567 



— 2-796 



- 4-459 



- 3-711 



- 4-178 



- 6-463 

 -f 10-739 



