The ocean, atmosphere, and life
478 LIFE.
CHAPTER XXIH.
THE   DRAINING OF  LAKES AND INLETS  OF THE SEA.—THE   LAKE  OF COPAIS,
THE   LAKE   OF   FUCINO, THE   SEA   OF   HAARLEM,  THE   ZUYDER   ZEE. POL-
ENDERS.—THE PURIFICATION OF SALINE MARSHES.
Emboldened by the reclamation of marshy lands, agriculture wished
for more; its next requirement was to take possession of the beds of
lakes, and of low grounds occasionally covered by the sea-water. From
the earliest antiquity, great works of this kind have been undertaken;
twenty-two centuries ago, in the time of Alexander the Great, Krates the
engineer devoted himself to the task of entirely emptying the Lake of
Copa'is, in Bceotia. During a long series of dry years, this basin was often reduced to a few pools of marshy water, and tiny rivulets crept over
the plain between the reeds and rushes; but, on the contrary, in rainy
seasons it was a fine lake, with an area of several millions of acres, and
was constantly swelled by the torrents which came down from Helicon
and the other mountains in the vicinity. The water was separated from
the sea by a wide rampart of calcareous rocks, and found no means of outlet except by certain deep fissures, or Jcatavothra. Krates straightened
these so as to facilitate the flow ofthe water; but since this epoch they
have become again obstructed, and the projects which have been formed
in later days for restoring the work of the ancient Greeks have been all
in vain.
Modern engineering skill has been more fortunate on the soil of Italy
in resuming and finishing a great work of drainage which the Romans
were not able to bring to a happy conclusion. The lake of Fucino, situated fifty miles to the east of Rome, near the towns of Avezzano and Ce-
lano, occupies the centre of a circular range of hills in the Apennines,
formed like a crater, the slopes of which are covered with dwellings and
cultivated fields. Sometimes floods inundated all the country round and
destroyed the crops; and afterward, when the water ran off, the air was
filled with poisonous miasmas; the difference between the levels shown
during high floods and at low water was not less than thirty-nine feet.
During the reign of Claudius, 30,000 slaves worked for eleven years
in digging out a channel 6151 feet in length across Monte Salviano, in order to draw off the largest portion ofthe water into the Liris, and thence
into the sea. It was fully believed that the work had been happily
achieved so as to last for centuries, like the tunnel about one-third the
above-named length, which had been dug more than four hundred years
before from the Lake Albano, near Rome. All that now remained to be
done was to open the flood-gates. The emperor, vain as cruel, had prepared a splendid fete upon the lake; nineteen thousand gladiators, em-
Title The ocean, atmosphere, and life
Creator Reclus, Elisée
Publisher Harper
Transcript 478 LIFE. CHAPTER XXIH. THE DRAINING OF LAKES AND INLETS OF THE SEA.—THE LAKE OF COPAIS, THE LAKE OF FUCINO, THE SEA OF HAARLEM, THE ZUYDER ZEE. POL- ENDERS.—THE PURIFICATION OF SALINE MARSHES. Emboldened by the reclamation of marshy lands, agriculture wished for more; its next requirement was to take possession of the beds of lakes, and of low grounds occasionally covered by the sea-water. From the earliest antiquity, great works of this kind have been undertaken; twenty-two centuries ago, in the time of Alexander the Great, Krates the engineer devoted himself to the task of entirely emptying the Lake of Copa'is, in Bceotia. During a long series of dry years, this basin was often reduced to a few pools of marshy water, and tiny rivulets crept over the plain between the reeds and rushes; but, on the contrary, in rainy seasons it was a fine lake, with an area of several millions of acres, and was constantly swelled by the torrents which came down from Helicon and the other mountains in the vicinity. The water was separated from the sea by a wide rampart of calcareous rocks, and found no means of outlet except by certain deep fissures, or Jcatavothra. Krates straightened these so as to facilitate the flow ofthe water; but since this epoch they have become again obstructed, and the projects which have been formed in later days for restoring the work of the ancient Greeks have been all in vain. Modern engineering skill has been more fortunate on the soil of Italy in resuming and finishing a great work of drainage which the Romans were not able to bring to a happy conclusion. The lake of Fucino, situated fifty miles to the east of Rome, near the towns of Avezzano and Ce- lano, occupies the centre of a circular range of hills in the Apennines, formed like a crater, the slopes of which are covered with dwellings and cultivated fields. Sometimes floods inundated all the country round and destroyed the crops; and afterward, when the water ran off, the air was filled with poisonous miasmas; the difference between the levels shown during high floods and at low water was not less than thirty-nine feet. During the reign of Claudius, 30,000 slaves worked for eleven years in digging out a channel 6151 feet in length across Monte Salviano, in order to draw off the largest portion ofthe water into the Liris, and thence into the sea. It was fully believed that the work had been happily achieved so as to last for centuries, like the tunnel about one-third the above-named length, which had been dug more than four hundred years before from the Lake Albano, near Rome. All that now remained to be done was to open the flood-gates. The emperor, vain as cruel, had prepared a splendid fete upon the lake; nineteen thousand gladiators, em-