formed by the heated ascending column of air off the plain, sweeping the
valley of the Rhone, and reaching its maximum of intensity between Avignon
and the sea, where it meets, and is blunted in its force by the equable
atmosphere that covers the surface of the Mediterranean.

The violence of the wind is consequently due to the difference of
temperature between the hot air of the plain and the cold air of the
mountain.

An old saying was to this effect:--

"Parlement, Mistral et Durance
Sont les trois fleaux de Provence."

Parlement exists no longer, or rather is expanded into a National Assembly
that is a discredit to all France, and not Provence alone; the Durance has
become, thanks to Adam de Craponne, an agent of fertilisation and wealth.
But the _mistral_ (_magistral_, the master-wind) remains, and still
scourges the delta of the Rhone. In 1845 it carried away the suspension
bridge between Beaucaire and Tarascon; the passage of the Rhone is often
rendered impossible for days, through its violence. It has been found
necessary to plant rows of cypress on each side of the line that crosses
the Crau, to break the force of the wind upon the trains. Indeed,
throughout the district, the fields will, in many places, be found walled
up on all sides by plantations of cypresses from thirty to fifty feet high,
as screens against this terrible blast, to protect the crops from being
literally blown out of the ground.

When I was a child of five years my father's carriage with post horses was
crossing the Crau. It was in summer. I sat on the box with my father and