On the Danger of Hasty Generalization in Geology. 437 



forty years ago cultivated this identical bed before beds Nos. 

 6 and 7 were laid down. 



The question now arises, how were the beds 6 and 7 laid down? 

 Bed (6) was the il tail end" of Mount Falcon, raised by Oliver 

 Cromwell, and levelled over bed 5, Avhen the road was made for 

 the proposed advent of George IV. into Edinburgh in 1822. 

 Bed No. 7, Mr Geikie describes as consisting of a true beach 

 bed with all its shells and balani, and he is led to believe that 

 the deposit was truly laid down by the sea. There are, how- 

 ever, two facts which at once set this aside : 1. The balani are 

 often found on the stones with their valves downwards, instead 

 of exposed to their native element; and, 2, bed No. 7 was 

 taken out within eight years from the foundation of a house, 

 and entirely consists of the same shells, &c, which form bed 

 No. 1 of Mr Geikie's section, to which I shall now devote a 

 few words, showing that it was formed within the historic 

 epoch, and long after the advent of the Romans. From the 

 Ordnance Survey map I have taken various contour levels of 

 the streets and quays of Leith to the number of seventy-two. 

 These give an average height above mean high water of 28-7 

 feet. Now, as the tides vary from neaps to springs about 16 

 feet, we must deduct from this half the amount, equal to 8 

 feet; this leaves for average tides a height of 20 7. Now, as 

 the oyster bed of Mr Geikie, or rather his No. 1 (which I call 

 a storm-raised bed) is 15 feet below the average of the streets 

 of Leith, we have only to account for a storm-wave five feet in 

 height, to throw up their so-called raised sea-beach bed so 

 much insisted on by Maclaren and Chambers. 



Such conditions of the tides have often been observed by the 

 elder inhabitants of Leith, the effects of which could not of 

 course affect land lying below the houses. But let us suppose 

 the condition of Leith before or immediately after the Romans 

 laid the " Fishwife's Causey," and man had not placed barriers 

 against the sea, but that the piers, harbours, and houses of 

 Leith, with all their defences, were removed, old Ocean would 

 soon re-assert his former sway, and claim as his domain the 

 links of Leith, and leave at all high tides, and during N.E. 

 storms, effects equivalent to those which make this storm- 

 raised bed the stumbling-block of all geologists who attempt to 



