More Portuguese troops had been raised, and reinforcements received from England, so that the Allies, without the Spaniards above alluded to, now numbered some 75,000 men, and from near the Coa watched the Douro and Tormes, their line stretching from their left near Lamego to the pass of Banos, Hill being on the right.
Aristotle's vague knowledge of the worm may have been derived from information acquired by the Greeks with Alexander the Great; but long before this time raw silk must have begun to be imported at Cos, where it was woven into a gauzy tissue, the famous Coa vestis, which revealed rather than clothed the form.
36, if OA, OB, OC be three mutually perpendicular lines in the solid, we may denote by O the angle which OC makes with a fixed direction OZ, by ~ the azimuth of the plane ZOC measured from some fixed plane through OZ, and by f~ the inclination of the plane COA to the plane ZOC In fig.
Lesser ranges, which are included in the Beirene system and vary in height from 2000 to 4000 ft., are the Mesas, between the rivers Coa and Zezere; the Guardunha and Moradal, separating the Zezere from the Ponsul and Ocreza, tributaries of the Tagus; the Serra do Aire, and various ridges which stretch south-westward as far as the mountains of Cintra (q.v.).
The chief Portuguese tributaries of the Douro are the Tamega, Tua and Sabor on the north, the Agueda, Coa and Paiva on the south; of the Tagus, the Ocreza, Ponsul and Zezere on the north, the Niza and Sorraia on the south, while into the Guadiana, on its right or Portuguese bank, flow the Caia, Degebe, Cobres, Oeiras and Vascao.