"CRATER NECKS" AND "VOLCANIC BOMBS." 295 



Should this conglomerate prove to be, as I suppose, a 

 drift deposit altered by a subsequent flow of lava, it will 

 supply exceedingly interesting data for the determination 

 of the chronological relations of the glacial epoch to that 

 period of volcanic activity to which the lavas of the N.E. 

 of Ireland are due. Though it will nowise disturb the 

 general conclusion that the great eruptions that overspread 

 the cretaceous rocks of this region, and supplied the 

 boulders of my supposed metamorphosed drift, occurred 

 during the Miocene period, it will show that this volcanic 

 epoch was of vastly greater duration than is usually sup- 

 posed; or that there must have been two or more volcanic 

 epochs pre-glacial, as usually understood, and post-glacial, 

 in order to supply the lava overflowing the drift. 



This post-glacial extension of the volcanic period has an 

 especial interest in Ireland, as the " Annals of the Four 

 Masters," and other records of ancient Irish history and 

 tradition, abound in accounts of physical changes, many of 

 which correspond remarkably with those of recent occur- 

 rence in the neighborhood of active and extinct volcanoes. 



In a paper read before the Royal Irish Academy, June 

 23, 1873, and published in its "Proceedings," Dr. Sigerson 

 has collected some of the best authenticated of these ac- 

 'counts, and compares them with similar phenomena recent- 

 ly observed in Naples, Sicily, South America, Siberia, etc. 

 .etc. -The "great sobriety of diction, and circumstantial 

 precision of statement," of names, dates, etc., which charac- 

 terize, these accounts render them well worthy of the sort 

 of comparison with strictly scientific data which Dr. Siger- 

 son has made. . 



As we now know that man existed in Britain during the 

 inter-glacial, if not the pre-glacial period, and as so violent 

 a volcanic disturbance as that which poured out the lavas 

 of Antrim and the Mourne district could scarcely have 

 subsided suddenly, but was probably followed by ages of 

 declining activity, it is not at all surprising that this period 

 of minor activity should have extended into that of tradi- 

 tion and the earliest of historical records. 



