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 6and7 laid down'? 
Bed (6) was the tail end" of Mount Falcon, raised by Oliver 
Cromwell, and levelled over bed 5, when 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 Komans. 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 207. 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 
