Where the Tejo enters Portugal, below the magnificent bridge of Alcántara, it is still hemmed in between precipitous banks, and is neither navigable nor available for purposes of irrigation. Having traversed the defile of Villa Velha do Rodão, its valley gradually widens, and after having received its most considerable tributary, the Zezere, it becomes a tranquil stream, abounding in islands and sand-banks, and is navigable during the whole of the year. Below Salvaterra the river bifurcates, its two branches enclosing the marshy island of Lezirias. The vast estuary which begins below this island is an arm of the sea rather than a river; its waters are saline, and between Sacavem and Alhandra there are {483} salt-pans. The Tejo affords one of the most striking instances of a river encroaching upon its western bank, which is steep and hilly, whilst the left bank is low.

[Μ]

Fig. 198.—ESTUARY OF THE TEJO (TAGUS).

Scale 1 : 580,000.

The irregular range of hills which forms the back-bone of the peninsula enclosed by the Lower Tejo and the ocean is attached to the mountain of Estrella by a ravined plateau of trifling elevation, crossed by the railway connecting Coimbra with Santarem. From the summit of the Serra do Aire (“wind mountain,” 2,222 feet) we look down upon the verdant valley of the Tejo and the reddish-hued plains of Alemtejo beyond it. Monte Junto (2,185 feet), farther south, is another commanding summit. The rocky promontory of Carvoeiro is joined to the mainland by a sandy beach. Upon it stands the little fortress of Peniche, whose inhabitants lead a life of seclusion, and are engaged in the manufacture of lace. A submarine plateau connects this promontory with Berlinga Island, with an old castle now used as a prison, and with the Farilhãos, dreaded by mariners.

The hills on the narrow peninsula to the north of Lisbon are of small height, but, owing to their rugged character, they present great obstacles to in­ter­com­mu­ni­ca­tion. It was here Wellington constructed the famous lines of Torres Vedras, which converted the environs of Lisbon into a vast entrenched camp. To the south of these rise the beautiful heights of Cintra, celebrated for their palaces, shady valleys, delightful climate, and historical associations. Sheets of basalt, {484} ejected from some ancient volcano, cover the hills between Lisbon and Sacavem, and the great earthquakes of 1531 and 1755 prove that subterranean forces were then not quite extinct. The second of these earthquakes was probably the most violent ever witnessed in Europe. The very first shock destroyed 3,850 houses in Lisbon, burying 15,000 human beings beneath the ruins; a minute afterwards an immense wave, nearly forty feet in height, swept off the fugitives who crowded the quay. Only one quarter of the town, that anciently inhabited by the Moors, escaped destruction. The Marquis de Pombal erected a gallows in the midst of the ruins to deter plunderers. From the focus of vibration the oscillations of the soil were propagated over an immense area, estimated at no less than 1,000,000 square miles. Oporto was destroyed in part, the harbour of Alvor in Algarve was silted up, and it is said that nearly all the large towns of Morocco tumbled into ruins.

The gully which connects the open ocean with the inland sea of Lisbon, and through which the Tejo discharges its waters, separates the cretaceous hills of Cintra from the isolated Serra da Arabida (1,537 feet), to the west of Setúbal, which belong to the same geological formation. These two groups of hills were probably portions of one range at a time when the Tejo still took its course across what are now the tertiary plains of Alemtejo, and reached the sea much farther to the south, through the estuary of the Sado.

Lisbon (Lisbõa), though the number of its inhabitants is less than half what it was in the sixteenth century, exhibits no trace of the havoc wrought in 1755. Even the central portions of the town have risen from the ruins, and huge blocks of houses, imposing by their size, if not by their architecture, have taken the places of the older structures. The present city extends four miles along the Tejo, but including its suburbs, between Poco do Bispo and the Tower of Belem, its extent is nine miles. The city stretches inland a distance of two or three miles, and, like Rome, is said to be built upon seven hills. A beautiful promenade connects it with Belem. As seen from the Tejo, or from the hills opposite, Lisbon, with its towers, cupolas, and public walks, certainly presents a magnificent spectacle, and there is some truth in the proverb which says—

“Que não tem visto Lisbõa, Não tem visto cosa bõa !”