CONTENTS. 



VOLUME IV. 



I 



1847-1850. 



PAGE. 



Address of the Academy to the Earl of Clarendon, Lord Lieutenant 

 of Ireland 1 



Answer of the Earl of Clarendon to Address 2 



Letter from the Royal Commission for the Preservation of Antiqui- 

 ties, Copenhagen 4 



On the determination of Differences of Longitude, by Means of 

 Shooting Stars. By E. J. Cooper, Esq 6 



An Account of some additional Applications of Quaternions to Sur- 

 faces of the Second Order. By Sir William R. Hamilton. . . 14 



On the Sum of Eight Squares. By Professor Young 19 



Letter on the Exchange of an ancient English for an Irish Seal. By 

 William Staunton, Esq 20 



Letter from M. Elie Wartman of Geneva 21 



Letter relating to an ancient Irish Bell, presented to the Academy 

 by J. C. Deane, Esq 24 



On the Persian Cuneiform Character. By the Rev. C. W. Wall, 

 (V. P.)D.D 24 



On Etruscan Coins, in the Possession of Mr. Cooke of Parsonstown 



and Mr. Charles Haliday of Dublin. By Sir William Betham. . 29 



On the same. By the Rev. J. H. Todd, D. D 33 



On Hylurgus Piniperda. By Professor Allman 84 



Subscription for the Purchase of the Betham Collection of Irish MSS. 

 commenced 35 



On a Cinerary Urn found near Bagnalstown. By W. R. Wilde, 

 Esq 35 



Letter from Charles Haliday, Esq. to Sir William Betham on Etrus- 

 can Coins 36 



On a Meteor seen near Dublin. By George Yeates, Esq. ... 37 



On the Applications of Quaternion. By Sir W. R. Hamilton. . . 38 



