The Ancient Lakes of Edinhurgh. 129 



its deposits, to tlie most typical lakes within the immediate 

 range of our inquiry. Tlie times represented by these lake 

 silts or marls extend from the end of last century, as in the 

 cases of the North Locli and the Borough Loch, back to the 

 intergiacial lakes of Hailes and Kedhall. By the end of last 

 century is simply meant that about that time the North 

 Loch and the Borouoh Loch became extinct as lakes. As to 

 the time when they first became lakes, Hugh Miller's later 

 suggestion in 1854 — by which he amended his first suggestion 

 in 1842 by extending their period from the time of the 

 Noachian flood about 4000 years ago to the times of the later 

 upheavals of the land, which in the case of the higher lying 

 lakes might be four times 4000 years ago — must be taken as 

 the nearest approach to the actual date we can at present 

 make. The intergiacial lakes of Hailes and Eedhall must 

 be considerably earlier in date than any of the others, which 

 must all be reckoned postglacial ; but to put it in figures is 

 beyond our present intentions. 



The North Loch. 



The material from this lake was given to us in 1871 by 

 the late Mr J. Wallace Young, who obtained it from his 

 uncle, Mr Bell, for many years chief engineer of the North 

 British Eailway. It was taken from the excavations for the 

 new arrival platforms made at that time for the trains 

 coming from the west. We cannot give any details of the 

 thickness or extent of the deposit of which it was a part, but 

 as it is said that the North Loch stretched from the Castle 

 eastward to beyond the North Bridge, it was probably 

 extensive, and most likely represented several diverse con- 

 ditions determined by the depth and exposure of the water. 

 The material from which the shells and Ostracoda were 

 obtained was not marl as in most instances, but a brown 

 earthy mud, which did not separate into dust or grains, but 

 remained in small solid pellets even after boiling a consider- 

 able time. It is therefore evidently from the latest deposit 

 ere the loch was drained dry, and the life remains are probably 

 not more than 100 years old. AVhen the railway was made 

 VOL. X. I 



