DOI issue:
Ashby,T.: The classical Topography of the roman campagna. The via latina. Introduction
DOI Page / Citation link:https://doi.org/10.11588/diglit.70348#0025
Classical Topography of the Roman Campagna.—III. 9
particular difficulties to overcome, rising gradually. From the 9th to the
10th mile the ascent is somewhat steeper (118 to 173 metres) and from the
10th to the 13th it becomes still more considerable (173 to 408 m., or 257
English ft. in a mile). In all this distance, however, the country is
■comparatively easy, as it slopes up gradually towards the hills. About
the nth mile the road turns more and more to the E., until, by the time
the 13th mile is reached, it is running practically due E. At this point,
where the post-station of Roboraria should be sought, it enters the depres-
sion between the rim of the great outer crater of the Alban volcano and
the smaller and higher crater which was afterwards raised within it. See
■Geikie, Landscape in History and other Essays, 335 seq. ‘The Alban
Hills . . . consist essentially of one great volcanic cone of the type
of Vesuvius, with a base about 12 miles in diameter. This cone has been
so greatly truncated that its summit, from one side of the rim to the other,
measures about six miles. The highest point of the rim is 3071 feet above
sea-level.1 Inside lies the huge cauldron-like depression that formed the
original crater of the volcano, encircled with steep slopes and rocky walls
save on the north-west side towards Rome, where the continuity of the
crater-ring has been destroyed.
‘. . . . The explosion that eviscerated the Alban volcano .... was not
improbably followed by a long period of repose. But the subterranean
■energy was not exhausted, though it never again showed itself on so
vigorous a scale. We can trace, indeed, the signs of its gradual enfeeble-
ment. When it recommenced its activity the vent, which served as the
channel by which its eruptions took place, still retained its central position.
Round this vent a newer but much smaller cone, bearing witness to less
vigour of eruption, was built up in the middle of the crater. This younger
mass rises in Monte Cavo to a height of 3150 feet, the highest elevation
on the whole mountain.2 It encloses a well-marked crater with the flat
plain of the Campo di Annibale at its bottom. Eventually the central
■orifice came to be choked up by the lava that had risen and solidified with
it, and as the volcanic forces still sought an outlet to the surface, they were
compelled to find egress at other and weaker points of the volcano.
1 Monte Peschio, N. of Velletri (939 metres—really 3081 feet).
2 The Italian staff map (I : 25,000) as revised in 1894, gives the height of Monte Cavo as
949 m. (3113'57 feet) and that of the Maschio delle Faete E.S.E. of it as 956 m. (3136'54 feet).
[The same is the case on the I : 100,000 map.]
particular difficulties to overcome, rising gradually. From the 9th to the
10th mile the ascent is somewhat steeper (118 to 173 metres) and from the
10th to the 13th it becomes still more considerable (173 to 408 m., or 257
English ft. in a mile). In all this distance, however, the country is
■comparatively easy, as it slopes up gradually towards the hills. About
the nth mile the road turns more and more to the E., until, by the time
the 13th mile is reached, it is running practically due E. At this point,
where the post-station of Roboraria should be sought, it enters the depres-
sion between the rim of the great outer crater of the Alban volcano and
the smaller and higher crater which was afterwards raised within it. See
■Geikie, Landscape in History and other Essays, 335 seq. ‘The Alban
Hills . . . consist essentially of one great volcanic cone of the type
of Vesuvius, with a base about 12 miles in diameter. This cone has been
so greatly truncated that its summit, from one side of the rim to the other,
measures about six miles. The highest point of the rim is 3071 feet above
sea-level.1 Inside lies the huge cauldron-like depression that formed the
original crater of the volcano, encircled with steep slopes and rocky walls
save on the north-west side towards Rome, where the continuity of the
crater-ring has been destroyed.
‘. . . . The explosion that eviscerated the Alban volcano .... was not
improbably followed by a long period of repose. But the subterranean
■energy was not exhausted, though it never again showed itself on so
vigorous a scale. We can trace, indeed, the signs of its gradual enfeeble-
ment. When it recommenced its activity the vent, which served as the
channel by which its eruptions took place, still retained its central position.
Round this vent a newer but much smaller cone, bearing witness to less
vigour of eruption, was built up in the middle of the crater. This younger
mass rises in Monte Cavo to a height of 3150 feet, the highest elevation
on the whole mountain.2 It encloses a well-marked crater with the flat
plain of the Campo di Annibale at its bottom. Eventually the central
■orifice came to be choked up by the lava that had risen and solidified with
it, and as the volcanic forces still sought an outlet to the surface, they were
compelled to find egress at other and weaker points of the volcano.
1 Monte Peschio, N. of Velletri (939 metres—really 3081 feet).
2 The Italian staff map (I : 25,000) as revised in 1894, gives the height of Monte Cavo as
949 m. (3113'57 feet) and that of the Maschio delle Faete E.S.E. of it as 956 m. (3136'54 feet).
[The same is the case on the I : 100,000 map.]