3T0 



April 24. 

 SIR WILLIAM BETHAM, in the Chair. 



The Chairman informed the Academy, that Sir Richard 

 O'Donnell had consented to deposit the Cathach, containing 

 a MS. of the Psahiis in Latin, by St. Colombkill, in the Mu- 

 seum of the Royal Irish Academy. 



Resolved, — That the marked thanks of the Academy be 

 returned to Sir Richard O'Donnell for his kindness. 



Read, a letter from the Rev. T. R. Robinson, accom- 

 panying a box containing an original Pyrometer of Wedge- 

 wood, presented to the Academy by Miss Edgevvorth, 

 (H. M. R. I. A.) 



" Dear Mac Cullagh, 



" Our friend, Miss Edgeworth, has requested me 

 to present from her to the Academy a Wedgewood's Pyro- 

 meter, which, as unfortunately I cannot attend this evening, 

 I commit to your care. This instrument is remarkable, as 

 being the first attempt to place within reach of the manu- 

 facturer and the chemist an easy method of measuring, at 

 least approximatively, the temperature of their furnaces. It 

 consists, as is well known, of a pair of converging bars, which 

 measure, by a graduation on them, the contraction of clay 

 cylinders that have been heated ; this remains permanent, 

 and were it, as Mr. Wedgewood supposed, a function of 

 temperature alone, would suffice for all practical purposes. 

 Many circumstances, however, have interfered with its gene- 

 ral employment. The set of clay pieces which were used in 

 the first instance were made of natural clay found in Corn- 

 wall. By these the numbers given in treatises of chemistry 

 for the fusing points of the more refractory metals were de- 

 termined, and I think it probable that Mr. Kirwan used them 

 in his researches; Sir James Hall, I think, did not. Mr. 



