THE VAL DI CHIANA. 
419 
much in level. The general inclination of the valley was 
therefore small; it does not appear to have ever been divided 
into opposite slopes by a true watershed, and the position of 
the summit seems to have shifted according to the varying 
amount and place of deposit of the sediment brought down 
by the lateral streams which emptied into it. The length of 
its principal channel of drainage, and even the direction of its 
flow at any given point, were therefore fluctuating. Hence, 
much difference of opinion was entertained at different times 
with regard to the normal course of this stream, and, conse¬ 
quently, to the question whether it was to be regarded as prop¬ 
erly an affluent of the Tiber or of the Arno. 
The bed of the latter river at the bend has been eroded to 
the depth of thirty or forty feet, and that, apparently, at no 
very remote period. If it were elevated to what was evidently 
its original height, the current of the Arno would be so much 
above that of the Paglia as to allow of a regular flow from its 
channel to the latter stream, through the Yal di Chiana, pro¬ 
vided the bed of the valley had remained at the level which 
excavations prove it to have had a few centuries ago, before it 
was raised by the deposits I have mentioned. These facts, 
together with the testimony of ancient geographers which 
scarcely admits of any other explanation, are thought to prove 
that all the waters of the Upper Arno were originally dis¬ 
charged through the Yal di Chiana into the Tiber, and that a 
part of them still continued to flow, at least occasionally, in 
that direction down to the days of the Roman empire, and 
perhaps for some time later. The depression of the bed of the 
Arno, and the raising of that of the valley by the deposits of 
the lateral torrents and of the Arno itself, finally cut off the 
branch of the river which had flowed to the Tiber, and all its 
Popular traditions and superstitions are so closely connected with local¬ 
ities, that, though an emigrant people may carry them to a foreign land, 
they seldom survive a second generation. The swallow, however, is still 
protected in New England by prejudices of transatlantic origin; and I 
remember hearing, in my childhood, that if the swallows were killed, the 
cows would give bloody milk. 
