334 



the sand dunes on the western shore, bones, oyster shells, &c, were 

 turned up by the plough. 



It may be perhaps vain to speculate who the tenant of the name- 

 less grave may have been. The sons of JSFessan, who gave their name to 

 this island, previously called " Inis Eaithlen," i. e. the Elder- tree Is- 

 land, doubtless rest here. In the year 701, Irgalach, regulus of the 

 Cianactha of Bregia, according to the Annals of Ulster and Tigernach, 

 was slain "on Inis Mac Nessan, east of Ben Edair," by the Britons, 

 who invaded his territory, and followed him to his retreat on this 

 island, where he was slain. Was he the tenant of this hastily- 

 made grave? Did he lack a friendly hand to close his eyes in 

 death? His burial may have been premature, and his struggles to 

 escape from his living tomb, when suspended animation returned, may 

 account for the unusual position in which these remains have been 

 found. The Irish Annals record various battles and sieges of which 

 Inis Mac JSTessan was the theatre during the ninth and tenth centuries, 

 interesting mementos of which were discovered during the past two 

 months. 



XXXIII. — On the Physical Conditions of Climate dtjeing dieeerenx 

 Geological Epochs. By PkoeessoeH. Hennessy, E.E.S. 

 [Abstract]. 

 [Read on 8th and 22nd June, 1868]. 



The author had briefly placed on record at different times since 1856 

 his conclusions as to the question which occupies his attention in the 

 present inquiry. His object in this paper is to submit to the Academy 

 a series of proofs of the correctness of his fundamental propositions 

 more elaborate and complete than he has hitherto attempted. The pro- 

 positions referred to may be thus summarised : The phenomena of Geo- 

 logical climate may be explained by the existence of two recognised 

 sources of heat. 1. Outer, that of the sun; 2. Inner, that of the 

 earth's cooling mass. 



By studying the facts revealed by Geological observations as to the 

 variations in the heat receiving and heat distributiug materials of the 

 earth's outer coating — namely, the solid crust, its watery envelope, and 

 the atmosphere — the author endeavours to show that the differences of 

 Geological climate necessarily result from such variations, and do not 

 require for their explanation any hypotheses of great cosmical revolu- 

 tions. Primary importance is attached to the action of water as a 

 receiver and carrier of heat derived from inner and outer heat sources ; 

 and the author called attention to the fact, that, since he had first ven- 

 tured in 1856 and 1857, to maintain the climatal influence of hydro- 

 thermal action, similar views have been reproduced by several eminent 

 inquirers. 



