1902. Porter. — Geographical Evohdioji in Cork. 155 



during glacial times. Shortly afterwards I met with Carvill 

 Lewis's observations on the Lee and Blackwater ('* Glacial 

 Geology of Great Britain and Ireland," p. 139). He says : — 



'' It is clear that the River Lee in glacial times flowed from 

 Queenstown Junction by Middleton to Youghal, as an open 

 drift-filled valley runs that wa3^ A somewhat similar 

 explanation suggests itself for the remarkable course of the 

 Blackwater from Cappoquin to Youghal." 



The case, how^ever, did not seem so clear to a local student 

 as to the distinguished American glacialist ; and I did not give 

 up Jukes's theory until further evidence was forthcoming. I 

 have recently found that the pre-glacial bed of the Lee has been 

 eroded in rock at the city of Cork to a depth of 66 feet below 

 the present ordnance datum,while the rock-sill of the present 

 exit of the river at Roche's Point, 14 miles further down, is 

 only 3 feet lower. It is obvious from these facts that the 

 river could not have taken that course in pre-glacial times. 



The construction of a contour map of the country by means 

 of the dotted altitudes on the six-inch sheets, recently put me 

 on the track* of some fresh diversions of the east Cork rivers, 

 which I have been able to verify. The upper Lee pursued a 

 pre-glacial course along the route of the present Macroom Rail- 

 way through the broad valley of the Bride, instead of its present 

 constricted course by Carrigadrohid, Coachford, and the ravine 

 of Inniscarra to the point where it now joins the Bride. The 

 Bandon originally turned due east at Dunderrow, 5 miles 

 above Kinsale, following a broad strath which leads past 

 Belgooly to Ringabella Bay. The Owenboy, which now 

 pursues an easterly course to Carrigaline, formerly consisted 

 of an eastern and a western trunk, which united at Fivemile- 

 bridge and flowed southwards to join the Bandon at Belgool3^ 

 The pre-glacial course of the Argideen lay to the west of 

 Clonakilty into the bay south of the town. 



The cause of the diversion has been the same in all cases. 

 Great masses of drift w^ere deposited in the original straths ; 

 and the waters, thus dammed back, accumulated to form lakes, 

 which found exits over neighbouring wind-gaps. The 

 obstructing masses of drift are easily traced in every case. 

 The Blackwater was blocked by the deposits of glaciers from 

 the Knockmealdowns as Carvill Lewis suggested. The Lee, 



A 2 



