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Hieetnson.—On Floods in Lake Districts. 185 
what will eventually prove more serious, should the destruction of timber 
not be checked, many of the streams will dry up during the summer 
months. 
The Commission of Italian engineers which has lately investigated the 
cause of the recent terrible floods in the River Po, reported that during the 
present century these floods have been progressively increasing in height ; 
that the expedient of attempting to confine them within the channel of the 
river by continual additions to the height of the artificial banks, has been 
considered inapplicable, as being a method tending to increase the very 
dangers it is intended to prevent. 
For this reason the object sought by the commission was rather the 
reduction of the floods themselves, or at all events the arrest of their 
increase. This involved the investigation of the influence on the volume 
of the river of the denudation of the growth of wood on its banks; the 
suggestion of legislative measures; the construction of storage basins or 
lakes to retain the flood-water for subsequent distribution for the purposes of 
irrigation, together with numerous other matters affecting the river. The 
result of this examination was that they estimated it was necessary to spend 
£600,000 in strengthening and restoring the banks, and a further sum of 
£320,000 for subsidiary works. 
Another Commission also lately appointed to report on works necessary 
to prevent inundation of the River Tiber in Rome, had the following pro- 
posed remedies to investigate and report on— 
1. Re-wooding the banks of the Tiber 
2. Storage lakes or basins of reserve 
3. Total deviation of the course of the Tiber 
4, Partial diversion of the water 
5. Limitation of the flow through the city 
6. Rectification of the channel : 
7. Additions to the banks and lateral defences. 
The Commission decided to increase the discharging capabilities of the 
two channels existing, by widening and clearing the bed within the city and 
embanking and regulating the course above it. M 
These particulars are obtained from the Italian Civil Engineers' Journal, 
and a writer in the same remarks, with reference to the remedies mentioned 
in the before-mentioned list, that with regard to the first remedy of re- 
wooding the banks too little is known of the requisite details, and that the 
result of any operation of this nature would be too slow in its development 
for it to be relied on as a prevention of flood ; as to the second proposal of 
storing storm water in artificial lakes, the only experience cited in modern 
limes is in the basins of the Upper Loire in the south of France, which 
works were executed in 1711. x 
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