ON THE COASTS OF IRELAND. 5 



19. Dunniore East. — A small port on the west side of the entrance of Waterford 

 Harbour (the confluence of the rivers Barrow and Suir) ; latitude 52° 9', longitude 

 6° 59'. The gauge was nailed to the pier. 



20. New Ross. — A town on the river Barrow ; latitude 52° 24', longitude 6° 56'. 

 The gauge was nailed to the bridge. 



21. Passage West. — ^This is the western side of the narrow channel by which the 

 waters of the river Lee, at Cork, principally enter into the broad harbour of Cork. 

 Its latitude is 51° 53', longitude 8° 21'. The tide-gauge was nailed to the face of the 

 steam-boat wharf. 



22. Castle Townsend. — A small harbour at very nearly the southernmost point of 

 Ireland ; latitude 51° 30', longitude 9° 20'. The gauge was a pole in the sea. 



Of these stations it may be remarked that Kilbaha, Kilrush, Foynes Island, and 

 Limerick, are four stations in succession on the same river ; that Dunmore East and 

 New Ross are on the same river ; and that Port Rush and Carrowkeel are nearly in 

 the same circumstances : Casleh Bay and Galway are in a relation nearly resembling 

 this. Kilbaha, Casleh Bay, Old Head, MuUaghmore, Port Rush, Ballycastle, Gleu- 

 arm, Donaghadee, Ardglass, Clogher Head, Kingstown, Courtown, Dunmore East, 

 and Castle Townsend, are all on the open sea ; Kilrush, Galway, Buncrana, Carrow- 

 keel, and Passage West, are somewhat removed from it. 



The zero of the tide-gauge at each place was referred as early as possible in the 

 course of the observations to a permanent mark (usually a copper bolt driven into 

 the face of a rock), and these marks were all connected by a system of levellings, 

 and thus the zeros of the tide-gauges were all referred to the same mark, namely, a 

 copper bolt fixed in the upper surface of the heelstone or hinge-stone of the gate of 

 Buckingham Lock, Dublin. To give the means of recovering this important zero, 

 in the event of its loss, the following references were made to several public buildings 

 in or near Dublin : — 



Building. 



Four Courts 



General Post-Office 

 Bank of Ireland . . . . 

 Custom House . . . . 

 Carlisle Bridge . . . . 



Queen's Bridge . . 



Trinity College . . 

 Poolbeg Light House 



Position of the mark on the building. 



Pavement or floor of portico at principal entrance 



Pavement or floor of portico 



Pavement or floor of colonnade at principal entrance 



Pavement or floor of portico at principal entrance 



Copper bolt driven horizontally into the stone-work of the battlement, 

 3-900 feet below the top of the battlement, and 2'840 feet above the 

 centre of the road 



Copper bolt driven horizontally into the stone-work of the battlement, 

 4-450 feet below the top of the battlement, and 1-580 foot above the 

 centre of the road • • • 



An arrow cut on the stone-work at the principal entrance in College Green, 

 3-300 feet above the surface of the ground 



A mark on the surface of the base-course, under the south window (the 

 mark lower than the bolt at Buckingham Lock) 



Elevation of 



the mark above 



the bolt at 



Buckingham 



Lock. 



feet. 

 + 0-928 

 -f 3-1 45 

 + 6-113 

 + 2-195 



+ 8-705 



+ 8-019 

 + 4-026 

 -0-020 



