their retreat. Some of its hills are still crowned with the imposing ruins of ancient Crusader castles. Al-Nahr al-Kabir marks the present political boundary between the republic of Lebanon and Syria.
The western range rises to alpine heights in the Lebanon massif, which extends more than 100 miles to the Litani river north of Tyre. The name Lebanon (Lubnan) comes from a Semitic root meaning 'to be white', and refers to the snow which now caps its peaks for about six months of every year. Mount Lebanon, of which the highest peak rises to over 11,000 feet, shelters the last surviving large grove of ancient cedars, resting in an amphitheatre representing the terminus of a prehistoric local glacier.
The rocks of Lebanon comprise an upper and a lower limestone series with an intermediate sandstone. The lower limestone forms the bottom of the deepest valleys, but elsewhere has been elevated by folding and reaches a height of about 9000 feet at Mount Hermon. On its surface are often found lumps of iron ore, the smelting of which has been carried on in rude furnaces up to recent times and has contributed to making Lebanon as bare of trees as it is. Mixed with clay and irrigated by water, this limestone provides fertile soil for the fruit and mulberry orchards on which much of the prosperity of the maritime plain around Beirut has been based.
The sandstone layers range in thickness from a few hundred to a thousand feet. They are devoid of fossils but have thin strata of lignite which has been mined in modern times to supply fuel for silk factories and for the railway during the first World War. This complex of sands and clays retains the rain water which seeps through the upper limestone and emerges in sparkling gushing springs that bestow their life-giving contents upon the slopes and valleys.
It is the limestone of the upper strata that has, through the ages, dominated the Lebanese scene, forming the summits and giving the landscape a greyish tone. Its erosion has
