354 



Proceedings of the Royal Irish Academy. 



The months of August and September, 1880, shall supply our 

 next quotations : — 



Date. 



Calcu- 

 lation. 



Obser- 

 vation. 



Error. 



Barom., Wind, &c. 



1880. 





ft. in. 



ft. in. 



in. 





Aug. 24, 



M. 



27 



8 



27 



6 



- 2 



30-4, ^.W., slight. 





E. 



25 



6 



25 



6 







„ N., 



25, 



M. 



26 



1 



26 







- 1 



)J ?) 5) 





E. 



24 







24 



3 



+ 3 



30-3, S., Bar. falling. 



26, 



M. 



24 



2 



24 



3 



+ 1 



30-2, ,, slight. 





E. 



22 



6 



22 



10 



+ 4 



„ S.W., „ 



27, 



M. 



22 



7 



22 



4 



- 3 



30-3, calm. 





E. 



20 



10 



21 



1 



+ 3 



30-4, N.W., fresh. 



28, 



M. 



20 



5 



20 



4 



- 1 



30-5, „ slight. 





E. 



19 



2 



19 



7 



+ 5 



>j E., ,, 



29, 



M. 



18 



8 



18 



9 



+ 1 



30-4, N.E., 





E. 



18 



7 



18 



4 



- 3 



30-3, ,, fresh breeze. 



30, 



M. 



18 



8 



18 



8 







30-2, E., slight. 





E. 



19 



4 



19 



9 



+ 5 



V s., ,, 



31, 



M. 



19 



6 



19 



7 



+ 1 



30-3, calm. 





E. 



20 



10 



21 



3 



+ 5 



30-4, S., slight. 



Sept. 1, 



M. 



21 



1 



21 



6 



+ 5 



„ S.S.W., fresh; 

 signal out. 





E. 



22 



6 



22 



7 



+ 1 



30-5., S., slight. 



2, 



M. 



22 



10 



22 



7 



- 3 



30-6., S.W., sHght. 





E. 



24 



3 



24 



2 



- 1 



>? >) J J 



3, 



M. 



24 



4 



24 







- 4 



30-5, KW.W., slight. 





E. 



25 



8 



25 



5 



- 3 



30-4, calm. 



4, 



M. 



25 



6 



25 



6 







30-3, S.S.W., calm. 





E. 



26 



11 



26 



10 



- 1 



30-2, S.W., slight. 



5, 



M. 



26 



5 



26 



6 



+ 1 



„ S.S.W._, gusty. 





E. 



27-9 



27-4 



- 5 



, , depression ap- 

 proaching. 



In conclusion, it is only necessary to observe how important it is 

 not only to ascertain the normal height of the tide, but also the 

 amount of the correction to be applied in consequence of atmospheric 

 disturbances. Where so many causes are combined, nothing but 

 patient experience and judgment will effect this. The most likely 

 means of obtaining an accurate prediction is to notice the successive 

 changes of sea-level from day to day, and add or subtract accordingly. 



