416 DKAESriNG OF LAKE CELAI^O. 



for some centuries.* In tlie barbarism wbicli followed tbe down- 

 fall of the empire, it again fell into decay, and though numerous 

 attempts were made to repair it during the Middle Ages, no 

 tolerable success seems to have attended any of these efforts until 

 the present generation. 



Drmnmg of Lake Gelam^o hy Prince Torlonia, 



Works have been some years in progress and are now sub- 

 stantially completed, at a cost of about eight millions of dollars, 

 for restoring, or rather enlarging and rebuilding, this ancient 

 tunnel, upon a scale of grandeur which does infinite honor to 

 the liberality and public spirit of the projectorsj and with an 

 ingenuity of design and a constructive skill which reflect the 

 highest credit upon the professional ability of the engineers who 

 have planned the works and directed their execution. The length 

 of the Roman tunnel was 18,634 feet, or rather more than three 

 miles and a half, but as the new emissary is designed to drain 

 the lake to the bottom, it has been laid at a lower level and con- 

 tinued to the lowest part of the basin by an open canal. The 

 new tunnel has a total length of about 21,000 feet, and, of course, 

 is among the longest subterranean galleries in Europe. Many 

 curious particulars in the design and execution of the original 

 work have been observed in the course of the restoration, but 

 these can not here be noticed. The difference between the low- 

 est and highest known levels of the surface of the lake is rather 

 more than forty feet, and the difference between the areas cov- 

 ered by water at these levels is not less than nine thousand acres. 

 The complete drainage of the lake, including the ground occa- 

 sionally flooded, will recover for agricultural occupation, and per- 

 manently secure from inundation, about forty-two thousand acres 



* The fact alluded to in a note on p. 95, ante, that since the opening of a 

 communication between Lake Celano and the Garigliano by the works noticed 

 in the text, fish, of species common in the lake, but not previously found in 

 the river, have become naturalized in the Garigliano, is a circumstance of 

 some weight as evidence that the emissary was not actually open in ancient 

 times ; for if the waters had been really connected, the fish of the lake would 

 naturally have followed the descending current and established themselves in 

 the river as they have done now. 



