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110 THE HONGKONG GOVERNMENT GAZETTE, 17TH FEBRUARY, 1883.

this disaster is very great, and cannot be considered as temporary only. Public assistance and private charity in Italy have come in aid of the sufferers, but much still remains to be done to heal the wounds that the floods have inflicted, and foreign help would, doubtless, be most gratefully received. The sanitary condition of the inundated provinces may also give cause for anxiety.

In the midst of the sudden confusion caused by the inundations, the authorities of every grade appear to have done their duty, the conduct of the army being especially deserving of praise. Wherever life and property had to be saved, where provisions had to be carried, or where the embank- ments had to be defended, there the troops were to be found working with courage and abnegation under the command of their officers.

I have, &c.

(Signed) D. E. COLNAGHI.

No. 2.

My Lord,

Consul-General Colnaghi to Earl Granville.—( Received October 26.)

Florence, October 23, 1882.

In continuation of my despatch of the 20th instant, relating to the recent inundations in North Italy, I have the honour to add some obscrvations taken from an Italian periodical, "The Bulletin of the Triennial Society for the Promotion of Silviculture in Italy,"* on the augmentation of floods since the mountains have been disforested. The Society of which this "Bulletin "is the organ was founded by the Senator Torelli, author of the great map of the malaria in Italy, and it has at its head, as Honorary President, Signor Quintino Sella, the well-known Italian statesman. I have endeavoured to summarize, as briefly as possible, the writer's remarks, which he has to preface with the confession that the Society has failed to interest the Italian public in its object.

"The 'Bulletin' was founded for the purpose of attracting, if possible, public attention to one of the great causes of inundations, the inconsiderate destruction of woods and forests. With this view a few gentlemen formed an experimental Society to last for three years only, hoping to constitute later a permanent association. The experiment has unfortunately failed, and the Society will cease to exist in the month of April next.

"The immediate cause of the recent inundations, the disastrous consequences of which will be felt for many years to come, was the heavy rains that fell on the North-eastern Alps during the second and third decades of September last, but their effect was greatly aggravated by the denuded condition of the mountains. From a well-wooded mountainous area the same mass of water would not have been precipitated to the plain with equal velocity as was the case from an area bare of trees. It is evident that, where woods exist, a certain quantity of water must be absorbed by the vegetation, while the larger portion, though it indeed descends, does so gradually, thus making an important difference in the volume of the floods. Paleocapa, the distinguished Venetian engineer, placed this truth in evidence, as far back as 1845, in a lecture delivered at the Venetian Institute of Sciences, Literature, and Art, on the diminished carrying capacity ('portata') of rivers. Citing as examples the Venetian rivers Sila and Brenta, he proved that their carrying capacity was diminished, and that the floods were higher and the average flow lower than formerly, which he unhesitatingly attributed to inconsiderate disforesting on the mountains.

"Another Italian celebrity, Lombardini, has furnished almost. mathematical proofs of the same fact, in his studies on the Lake of Como. The Como basin, containing a superficial area of about 70 square kilom...receives eight-tenths of its waters from the great valley of the Adda, which extends for more than 100 kilom. from Colico, near which place the river discharges its waters into the lake, to Bormio, where it has its source. The Adda has more than fifty tributary streams, between rivers and torrents, and, through its long course, varies from a minimum, discharging into the lake 14,000 cubic metres in the twenty-four hours, to a maximum, discharging 70,000 cubic metres within the same period. Numerous small torrents, which, in ordinary times, are almost always dry, become rapidly swollen after heavy rains, even of short duration, and the Adda as suddenly rises. Lombardini proved that the floods of the Lake of Como were in strict relation to the cutting down of the woods, which was effected, in the valley of the Adda, between 1825 and 1850. He showed that, in the early part of that period, there was only one flood every three years and a-half; then, every two years; later on, the average period between each flood was only eighteen months; and so, in gradation, with the dis- appearance of the woods, the floods became more frequent. Paleocapa's observations in Venetia pointed to a similar conclusion. The same quantity of water was distributed in a different manner; it accu- mulated with greater rapidity, and, in consequence, the floods recurred oftener and were more dangerous in character than when the woods existed.

"While, however, Italy is still blind to the danger arising from this denudation, such is not the case with her neighbours. Austria, Switzerland, and France have turned their serious attention to the reforesting of the bare mountain slopes, and, it would appear, not without success.

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*Bollettino della Società Triennale Promotrice della Silvicoltura in Italia." Anno III, Num. 56-57. Roma, Ottobre 1882.