237 
difficulty. From its great weight, and the curious adjustment 
of its balance, it seems to exhibit an amount of engineering 
and mechanical skill in its construction which is utterly- 
incomprehensible. Professor Wilson, the well-known author 
of the " Pre-historic Annals of Scotland," when describing 
the rocking stone, says : — " There is so strange a mixture 
of extreme rudeness, and great mechanical skill in these 
memorials of the remote past, that they will excite greater 
wonder and awe in the thoughtful mind, than even the 
imposing masses inclosing the sacred area of Stonehenge. 
It would I imagine prove a much more complicated problem 
for the modern engineer, to poise the irregular and amorphous 
mass on its point of equilibrium, than to rear the largest 
monolithic group, that now stands to attest the mechanical 
power which the old builders could command." The theory 
which I have here advanced for the formation of the primitive 
cromleach, would readily solve Professor Wilson's " compli- 
cated problem," and remove all his mechanical difficulties. 
If the glacial flood, of which we have everywhere such 
manifest indications, had borne away upon its enormous ice- 
rafts vast masses of rock torn from the abraded sides of the 
valleys as they drifted through them, these large blocks of 
stone must have been all again deposited on the bottom of 
this icy sea, on its increase of temperature and subsidence. 
Now many of these floating boulders must, as stated before, 
have fallen upon others, and sometimes thus breaking them, 
rested securely upon the fragments. Is it unreasonable to 
suppose that occasionally some may have been deposited 
quietly upon the very pivot of their centres of gravity, 
where they might have remained curiously balanced on the 
retreat of the waters ? They would thus become objects of 
•awe and veneration to the savage human creatures who first 
beheld them, and to all succeeding generations. In fact, we 
learn that the rocking stone was so regarded by the 
