PHYSICAL GEOGRAPHY OE THE IONIAN ISLANDS. 468 
as one broken surface is cleared off another is ready, preserving 
the same general appearance, though with materials constantly 
changing. 
It was an interesting point to discover, if possible, the time 
required for this destruction in any particular case, and though 
not easy in a single observation, there are means at hand in 
these islands which help greatly an estimate. Such are the 
ancient walls of cities celebrated in history, but of which 
absolutely nothing now remains but vast blocks of stone piled 
in regular order, and originally serving as a defence against 
the most approved mode of attack in then day. The latest 
period of the most complete work of this kind is more than 
two thousand years ago. No doubt at that time the walls of 
the ancient Samos in Cephalonia, attacked by the Romans and 
resisting for four months the most strenuous attacks of M. 
Fulvius, were in good condition ; and therefore, in looking at 
their present state, we see the work of twenty centuries, or 
thereabouts, of weathering. Of the buildings enclosed within 
the wails, some may have been built, and all, no doubt, were 
covered in with tiles ; for the whole soil is so mixed up with 
fragments of burnt clay, that the stones, however abundant, 
are hardly noticed. The ground is literally covered with pale 
red fragments of burnt clay, and as brick is less liable to 
injury than limestone from weathering 1 , there is good reason 
for this. But although a place where stone is so infinitely 
abundant, and in a country whose inhabitants were certainly 
familiar enough with the mode of working it, so that there was 
every possible reason for stone having been used for all kinds 
of constructive purposes, hardly one fragment of stone-worlc 
has been discovered either on the surface or buried, except the 
walls themselves. And there is but one explanation — every- 
thing else has been worn to powder by weathering. In the 
ruins below, where the Romans established themselves and 
remained for a long time, it is curious to see how well their 
work has been kept when consisting of bricks and mortar, or 
even terra-cotta of the commonest kind ; but there also, except 
a fragment or two of statuary sheltered amongst the ruins, 
there are no worked stones. 
The reason why the walls still remain, in spite of the absolute 
annihilation of every other sculptured stone, one has not far 
to seek. The whole design and construction of these walls is 
on a scale so gigantic as to have fairly resisted the efforts of 
decay in many parts, while in others it has partially yielded ; 
and it is this partial destruction which renders the whole in 
some measure a scale by which to estimate the rate of decay. 
The walls are of the kind called Cyclopean — composed of hewn 
stones of size so gigantic that no one in modern times has 
