The valley of the Po is frequently spoken of as Upper Italy, because it occupies the northern portion of the peninsula, but might more appropriately be termed the Italian Netherlands, for its elevation is less than that of any other group of provinces. It is a river valley now, but during the Pliocene epoch it still formed a gulf of the sea. This gulf was gradually filled up by the alluvium brought down by the rivers, and upheaved by subterranean forces above the surface of the waters, the erosive action of the mountain torrents continuing all the while; and thus, in the course of ages, the basin of the Po assumed its gentle and regular slope towards the sea. As long as the waters of the Adriatic penetrated the valleys between Monte Rosa and Monte Viso, Italy was attached to the Alps {190} of continental Europe only by a narrow neck of land formed by the Ligurian Apennines.

No other region of Europe can rival the valley of the Po as regards the magnificence of its distant prospects. The Apennines in the south raise their heads above the region of forests, their rocks, woods, and pasturages contrasting with the uniform plain spread out along their foot; whilst the snow-clad Alps rise in all their sublimity from the Col di Tenda in the west to the passes of Istria in the east. The isolated pyramid of Monte Viso (thus called from the beautiful prospect which may be obtained from its summit) looks down upon the fields of Saluzzo, and the small lakes in its pasturing region feed a roaring rivulet which subsequently assumes the name of Po. Enormous buttresses to the north-west of Turin support the ice-clad Grand Paradis, near which peeps out the Grivola, perhaps the most charming, the most gracefully chiselled of all Alpine peaks. Right in the bend of the Alpine chain rises the dome of Mont Blanc, like an island above a sea of mountains. Monte Rosa, crowned with a seven-pointed diadem, pushes its spurs far into Italy. Then come the Splügen, the Ortler, the Adamello, the Marmolade, and many another summit distinguished for some special beauty. When from the top of the dome of Milan we behold spread out around us this magnificent amphitheatre of mountains rising above the verdant plain, we may well rejoice that we should have lived to contemplate so grand a scene.

Geographically the Alps belong to the countries which surround Italy. From the south we seize at a glance the entire slope of the mountains, from the vineyards and plantations of mulberry-trees to the forests of beech and larch, the pastures, the naked rocks, and the dazzling fields of ice. But the cultivator only ventured into this difficult region when forced by poverty. The features of the northern slope are quite different. There the land rises gradually, and the valleys are less fertile, but the inhabitants can easily reach the heads of the passes, whence they look down upon the inviting plains of Italy. It is this structure of the Alps which explains the preponderance of the Germanic and Gallic elements throughout their extent, and whilst Italian is spoken only in a few isolated localities beyond this mountain barrier, the French and German elements are largely represented on their inner slopes.

Italy can only claim a few Alpine mountain masses within the basin of the Po, the Adige, and the rivers of Venetia. The most important of these, alike on account of its height, its glaciers, and springs, is the Grand Paradis, which rears its head to the south of the Dora Baltea, between the masses of Mont Blanc and the plains of Piemont. An Englishman, Mr. Mathews, may claim to be the first discoverer of this mountain giant, which even on the Sardinian staff map, published only recently, is confounded with Mont Iseran, a far less noble summit twenty-five miles to the west of it.

None of the other Alpine summits on Italian territory can compare in height with the Grand Paradis, for though the Italian language extends in numerous instances to the central chain of the Alps, the political boundaries of Italy do not. {191} Switzerland holds possession of the valley of the Upper Ticino, whilst Austria still possesses the Upper Adige. The only rivers rising on the southern slope of the Alps, and belonging in their entirety, or nearly so, to Italy, are the Tagliamento and the Piave. In consequence of this violation of the natural frontiers there are many snow-clad Alpine summits which, though geographically belonging to Italy, are situated on the frontiers of the present kingdom, or even within Swiss or Austrian territory. Amongst these are the giant summits of the Ortler, the Marmolade, and the precipitous Cimon della Pala. The Monte della Disgrazia, however, to the south of the Bernina, is an Italian mountain; such is also, for the greater part, the mountain mass of the Camonica, bounded on the north by the Pass of Tonale, which plays so prominent a part in legendary history, and is commanded by the Adamo, or Adamello, whose glacier streams creep down to the Upper Adige. Farther to the east, in the valley of the Piave, the obelisk surmounting the huge pyramid of the Antelao pierces the line of perennial snow, and there are other peaks scarcely inferior to it in height.

Most of the Alpine groups lying within Italy and between the main chain and {192} the plains do not exceed the Apennines in height, and only a few amongst them are covered with perennial snow. But the prospects which may be enjoyed from them are all the more charming for this reason, for we find ourselves between two zones, with cultivated valleys, towns, and villages at our feet, and a panorama of bare and snowy summits bounding the view to the north. Several of these mountains deservedly attract large numbers of tourists. Favourites amongst them are the hills rising above the blue lakes of Lombardy, such as the Motterone on Lago Maggiore, the pyramidal Generoso rising in the midst of verdant fields on the Lake of Lugano, the superb hills between the two arms of the Lake of Como and the fertile plains of the Brianza, and Monte Baldo, advancing its buttresses like lions’ claws into the waters of the Lake of Garda. The mountains of the Val Tellina, or the Orobia range, to the south of the valley of the Upper Adda, being remote from towns and customary highways, are less frequently visited than they deserve. Standing at their foot, we may almost fancy being in the Pyrenees. As to the dolomites, on the frontiers of Venetia and the Tyrol, they are unique. Their fantastically shaped rocks, delicately tinted with pink and other colours, contrast marvellously with the green of beeches and firs, or the blue waters of the lakes. Richthofen and others look upon these isolated mountain masses as ancient coral islands, or atolls, upheaved to a height varying between 6,500 and 10,400 feet; and, whatever their geological origin may be, they certainly contribute much towards the beauty of the Alpine regions.

If we descend the Italian slope of the Alps, we pass gradually from the more ancient to the most recent geological formation, until we finally reach the alluvial plain. Metamorphic rocks, verrucano, dolomites, and other rocks overlie the granites, the gneiss, and the schists of the more elevated mountain masses. These are succeeded by beds of Triassic and Jurassic age. Lower still we meet with {193} terraces and hills composed of tertiary marls, clays, and conglomerates. Monte Bolca, so famous amongst geologists on account of its fossils, belongs to this formation.62 The whole of the plain of Lombardy and Piemont, with the exception of the isolated hillocks rising in it, and a few marine deposits near its margin, consists of débris brought down by the rivers. The depth of this accumulation is not yet known, for hitherto no borings have pierced it; but if we suppose the slopes of the Alps and the Apennines to continue uniformly, it would amount to no less than 4,130 feet. The two diagrams (Fig. 53) are intended to illustrate this feature. In the upper of these the heights are exaggerated tenfold; in the lower both the horizontal and the vertical scales are the same. A glance at this diagram reveals the astounding fact that the volume of this débris almost equals that of the existing mountain systems.

The vast plain stretching from the Adriatic to the foot of the Monte Rosa and the Viso may boast of its peninsulas, its islands, and even its archipelagos, as if it were a sea. The tertiary hills of Northern Monferrato, to the east of Turin, attain a height of 1,600 to 2,000 feet, and the valley of the Tanaro completely separates them from the Ligurian Alps and the Apennines. Even at the very foot of the Alps, as at Cavour and elsewhere, isolated granitic or porphyritic pyramids and domes rise in the midst of the plain sloping down towards the Po.63 The hump-backed Bosco Montello, to the south of the Piave, is another isolated hill; and on the banks of the Po may be seen a hillock of pebbles and marine sands, abounding in fossils, which bears the village of San Colombano and its vineyards. Several volcanic peaks, surrounded by cretaceous formations, rise in the midst of the plains to the east of the Lake of Garda. The craters of the Berici, near Vicenza, and of the Euganean Hills, near Padua, have not vomited {194} flames within the historical epoch, but the hot and the gas springs which issue from clefts in the trachytic and basaltic rocks prove sufficiently that volcanic forces are not yet quite extinct in that part of Italy. Earthquakes occur frequently in the neighbouring Alps, and particularly near Belluno and Bassano.

A similar volcanic zone extends along the northern slope of the Apennines, which bound the valley of the Po on the south. Hydrogen gas escapes from fissures in the rocks to the south of Modena and Bologna, and is utilised in several instances in the manufacture of lime, and for other purposes. These gas springs of Pietra Mala, Porretta, and Barigazzo were known by the ancients and during the Middle Ages as “fiery springs,” and they illuminated the path of the traveller overtaken by the night. Lower down the slope, almost on the verge of the plains, we meet with a line of mud volcanoes, or bombi, the most famous of which are those of Sassuolo, near Modena. The largest of these, that of Mirano, has no less than forty craters. The ancient gulf of the sea, now converted into a plain, is thus skirted by volcanic cones, mud volcanoes, hot springs, and deposits of sulphur. As high up as Piemont, and notably at Acqui, we meet with hot springs, attesting that volcanic activity is not yet altogether extinct.

The valleys of the Alps and the plains extending along their foot were filled, in a former geological epoch, with huge glaciers, descending from what was anciently the immense glacial region of Central Europe. There is not a valley between that of the Tanaro in the west, and that of the Isonzo descending from the mountains of Carinthia, but contains accumulations of débris carried down by the {195} glaciers, and now covered with vegetation. Most of these ancient glaciers exceeded those of the Monte Rosa and the Finsteraarhorn in extent, and several of them rivalled the existing glaciers of the Himalaya. If we would gain a notion of what the Alps were like during this glacial epoch, we must go to Greenland or to the Antarctic regions.

One of the smallest of these ice streams, that which descended from the mountains of Tenda in the direction of Cuneo, had a length of thirty miles. That which brought down the ice of Mont Genèvre, Mont Tabor, and Mont Cenis had twice that length, and its moraines formed a veritable amphitheatre of hills, locally known as regione alla pietre, or stony region. Farther north the streams of ice descending from the Pennine Alps between the Grand Paradis and Mont Blanc united in a single stream eighty miles in length, and spread over the plain far beyond Ivrea. The alluvial accumulation of this ancient glacier rises 1,100 and even 2,130 feet above the valley through which the Dora Baltea now flows. One of its lateral moraines, known as the Serra d’Ivrea, forms a regular rampart to the east of the river, eighteen miles in extent. Its slopes are now covered with chestnuts. The western ravine (Colle di Brossa) is less prominent, because it is inferior in height; but the frontal ravine, forming a complete demicircle, can still be traced readily. In the débris accumulated at the foot of this ancient glacier, rocks derived from Mont Blanc are mixed with others brought down from Mont Cervin. And yet it was but a dwarf when compared with the ancient twin glacier of the Ticino and the Adda, which extended from the Simplon to the Stelvio, filled up the cavities now occupied by the Lago Maggiore {196} and the Lake of Como, sent a lateral branch to the tortuous bed of the Lake of Lugano, and finally, after a course of from 100 to 120 miles, debouched upon the plain of Lombardy. The glacier of the Oglio was small in comparison with it, but it was exceeded by that of the Adige, the most considerable of all on the southern slope of the Alps. This river of ice, from the mountains of the Oetzthal, where it originated, to its terminal moraine to the north of Mantua, had a length of 175 miles. One of its branches descended towards the east, down the valley of the Drave, as far as where the town of Klagenfurt now stands. Its main stream filled up the cavity of the Lake of Garda, pushing along a formidable rampart of elevated moraines.

The hand of man is scarcely able to make an impression upon the vast accumulations heaped up by the action of the glaciers. The hills of Solferino, of Cavriana, and Somma Campagna, so often named in connection with battles, are nothing but débris brought down from the flanks of the Alps, and they were much higher formerly than they are now. {197}

Some of the erratic blocks were as large as houses, but, being used as quarries, they are fast disappearing. One of them at Pianezza, at the mouth of the Susa valley, is 80 feet long, 40 feet broad, and 46 feet high, and a chapel has been built upon it. The huge erratic blocks in the hills between the two arms of the Lake of Como have supplied materials for the monolithic columns of the churches and palaces in the environs. The slopes of the hills of Turin facing the Alps are likewise covered with erratic blocks.

When the glaciers retired into the upper valleys of the Alps, the soil which they covered was left bare, and the depressions now occupied by the beautiful lakes of Lombardy were revealed. These depressions, whose bottom even now sinks down below the level of the ocean, were formerly arms of the sea, in character very much like the fiords of Norway. That such was the case is proved by the presence, in every one of the Lombard lakes, of a sardine (the agone), which naturalists consider to be a sea fish. In Garda Lake, moreover, there still dwell two marine fishes which have adapted themselves to their new condition of life, as well as a small marine shell-fish.

The number of these Alpine lakes was much larger formerly, and those which still exist shrink from year to year. In Upper Piemont alluvial deposits have long ago filled up the lakes, and there now only remain a few pools of {198} water to indicate their site. The first sheets of water to which the term “lake” may fairly be applied are met with on both banks of the Dora Baltea (see Fig. 57). The little basin of Candia and the shallow Lake of Azeglio, to the west and east of the river, are the only remains of Lacus Clisius, which covered an area of several hundred square miles until its waters broke through the semicircular terminal moraine which bounded it on the south. The Dora Baltea formerly escaped from this lake in the south-east, its present course only dating from the fourteenth century.

Since this reservoir has been drained, the first lake of importance in the west is that of Verbano, very inappropriately called Lago Maggiore, or the “principal lake,” as that of Garda exceeds it in extent. Ancient beaches, at an elevation of 1,300 feet above the sea, prove that the waters of the lake have considerably subsided, and that its area was much larger formerly; and it curiously ramified with neighbouring lake basins, now merely connected with it by rivers. The ancient moraine at the foot of this lake, and through which the Ticino has excavated itself a passage, still rises to a height of 980 feet. {199}

Centuries elapsed before the changes which we now perceive were accomplished. Still they proceeded at a sufficiently rapid rate. Even now the alluvium carried down by the Ticino and the Maggia continually encroaches upon the Lago Maggiore. Seven hundred years ago the village of Gordola stood on the shore of the lake: it is now nearly a mile away from it. The landing-places of Magadino, at the mouth of the Ticino, have to be continually shifted, for the lake retires steadily. Only sixty years ago barges were able to receive their cargoes at a wharf nearly half a mile higher up than the present one. The Gulf of Locarno is gradually being separated from the main sheet of water by alluvial deposits brought down by the Maggia.

The Lario, or Lake of Como, which rivals the Maggiore by its beauty, is likewise being gradually silted up. In the time of the Romans the navigation extended as far as Summolacus (lake-head), the modern Samolaco. But the torrent of Mera gradually converted most of the upper extremity of the lake into an alluvial plain, whilst the alluvial deposits carried down by the Adda cut off the remainder from the main body of water. There now remains only the Lacus {200} Dimidiatus, or Lake of Mezzola, which is shrinking from year to year, and will finally disappear altogether. The miasmata rising from the swamps at the mouth of the Adda have frequently depopulated the environs, and the ruined fort of Fuentes, at the mouth of the river, built to defend the Val Tellina, was hardly ever more than a hospital for its fever-stricken garrison.

The south-eastern arm of the lake, that of Lecco, through which the Adda makes its escape to the south, has likewise been divided into a series of separate basins. Nature, which would convert these lakes into bottom-lands at no distant date, is being aided here by the works of man. The barrier which obstructed the free egress of the Adda has been cleared away, the structures of fishermen have been removed, and, in consequence of these and other engineering measures, the once-dreaded rises of the lake have been reduced to a minimum, and the southernmost of the lake basins, that of Brivio, has been converted into dry land. The large Lake of Brianza, which extended formerly far to the south-west, has likewise been partially drained, and there now remain only a few lakelets of small extent.

We know sufficient of the bottom of the Lake of Como to enable us to judge of the manner in which it is becoming gradually filled up with alluvium. The mud deposited in its northern portion has filled up all the original inequalities of the soil, and even in the centre of the lake, and in its south-eastern arm, the bottom is almost a perfect level. In the Como arm, however, which receives no tributary river of any importance, the bottom is still full of inequalities. These differences amply prove to us the geological agency of the rivers, which must terminate in the lake being converted into a bottom-land, with a river flowing through its centre. The third of our diagrams (Fig. 62) shows that the greatest depth now hardly exceeds 1,300 feet, whilst, if we may judge from the slopes of the hills which bound it, the depth in former times cannot have been less than 2,300 feet.

The Sebino, or Lake of Iseo, and the lakelet of Idro, which are fed by the glacier streams of the Adamello, exhibit the same features as the lakes farther to the west. The Benaco, or Lake of Garda, however, the most extensive of these Alpine lakes, is very stable as regards its outline and the configuration of its bottom, a fact sufficiently explained by the small size of its tributary streams as compared with its vast area. The old Alpine lakes of the Venetian Alps have disappeared long ago, and there remain only a few ponds, filling cavities in the dolomitic rocks and peat bogs, to indicate their ancient sites.64 {201}

These lacustrine basins, like all other reservoirs of the same kind, regulate the outflow of the torrents which empty into them. During the freshets they store up the superabundant waters, and only part with them in the dry season, and upon their difference of level in different seasons depend the oscillations of the emissary rivers which issue from them. In the case of the Lake of Garda, which drains but a small area in proportion to its size, this difference is small, and throughout the year the pellucid waters of the Mincio flow tranquilly beneath the blackened ramparts of Peschiera. Such is not the case as regards either the Lago Maggiore or the Lake of Como, for the volume of water discharged into them is so considerable that their level in summer and winter varies to the extent of several yards, and corresponding differences may be observed in the rivers issuing from them. Lake Como rises no less than 12 feet, and increases 70 square miles in area, whilst the Lago Maggiore sometimes rises 22 feet, and {202} increases to the extent of one-fifth. The volume of the Ticino, when at its highest, almost equals the average volume of the Nile, and if it were not for the regulating influence of the lake from which it issues, it would alternately convert the plains of Lombardy into a sheet of water and leave them an arid tract of land.65

The Alpine lakes of Italy thus play an important part in the economy of the country. They render the climate more equable, serve as high-roads of commerce, and, being the centres of animal life, attract a dense population. But it is not this which has rendered these lakes famous, which has attracted thousands of wanderers ever since the time of the Romans, and caused villas and palaces to rise on their shores: it is their incomparable beauty. And, indeed, there are few spots in Europe which bear comparison with the delightful Gulf of Pallanza, over which are scattered the Borromean Islands, or with the peninsula of Bellagio, which may be likened to a hanging garden suspended within sight of the snow-clad Alps, and affording a prospect of the rock-bound shores of the Como Lake, cultivated fields, and numerous villas. Perhaps even more delightful is the peninsula of Sermione, jutting out into the azure waters of the Garda Lake, like the tender stalk of a flower developing into a many-coloured petal.

Most of the lakes in the plain have been drained into the neighbouring rivers. The Lake of Gerondo, mentioned in mediæval records, has dwindled down into a small swamp, or mosi, now, and its populous island of Fulcheria has become merged in the plain of Lombardy. The lakes on the southern bank of the Po, above Guastalla, have likewise been drained; and if the two shallow lakes of Mantua still exist, this is entirely due to the embankments raised in the twelfth century. It would have been much better, and would have saved the city the horrors of many a siege, if these lakes had been allowed to disappear likewise.

The lagoons along the Adriatic have decreased in extent in the course of centuries, and whilst new lagoons are being formed, the old ones are gradually being converted into dry land. The old maps of the Venetian littoral differ essentially from our modern ones, and yet all the vast changes they indicate have been wrought in the course of a few centuries. The swamps of Caorle, between the Piave and the Gulf of Trieste, have changed to an extent which prevents us from restoring the ancient topography of the country; and if the lagoons of Venice and Chioggia exhibit a certain permanence of contour, this is only on account of the incessant interference of man. The ancient lagoon of Brondolo has been dry land since the middle of the sixteenth century. The large lagoon of Comacchio, to the south of the Po, has been cut up into separate portions by alluvial embankments formed by the agency of rivers and torrents. For the most part it consists now of valli, or alluvial deposits, but there still remain a few profound cavities, or chiari, which the rivers have not yet succeeded in filling up. Formerly these {203} lagoons extended far to the south in the direction of Ravenna, and, according to Strabo and other ancient writers, that ancient city once occupied a site very much like that of Venice or Chioggia in our own days.