io6 



[Proc. B.N.F.C, 



gravel in many places. I am aware that in one of the Memoirs of 

 the Geological Survey (49, 50, 61, p. 13), Strangford Lough is set 

 down as having been formerly a fresh water lake, but no evidence 

 is adduced in support of this assertion. If it ever was such it 

 must have been at a remote period, as in the raised beach in the 

 neighbourhood I have frequently found marine shells. All people 

 engaged in scientific pursuits should beware of indulging in guesses 

 which are not supported by evidence. 



Islands similar to those that I suppose to have existed in the 

 Post-Glacial sea are at present to be met with in Strangford Lough. 

 These islands are very numerous, and according to the Memoir of 

 the Geological Survey they are formed of mounds of " boulder 

 clay." Whether any of them are formed of stratified material, such 

 as I have described, I have not been able to ascertain. Here we 

 have an excellent illustration of the effects produced by marine de- 

 nudation in inland seas. If the islands of Strangford Lough were 

 exposed to the fury of the Atlantic waves, they would soon be 

 swept away ; but they will probably be able for a long period to 

 resist the action of the calm waters with which they are surrounded. 

 Similar seas occupied all the low lands of our country and other 

 countries during the Post-Glacial period. These seas were studded 

 with islands, which, when the water retreated, appeared as rounded 

 hills. 



(2.) After hazing been submerged for a long period, the land slowly 

 rose, leaving lakes and swamps, which were ultimately covered with 

 peat in many places. 



The peat of this period was earlier than our present peat bogs, 

 which form so marked a feature in the landscape in many districts. 

 The town of Newtownards is situated on a bed of stratified gravel, 

 deposited by a former extension of Strangford Lough. A few years 

 ago, when making an excavation for a gasometer, a bed of peat 

 was discovered beneath the gravel, which at this place was four 

 feet thick. In the peat were found the trunk and roots of a large 

 tree, and beneath it was a deposit of fine sand. This succession 

 of beds will illustrate the order of events indicated above. The 



