Note 33 — Chapter V · GEOGRAPHICAL AND PHYSIOLOGICAL.

The daily run (مَجرا) native craft varies from 40 to 50 knots per diem, and 50 may be assumed as an average. Captain Guillain estimates it higher, from 48 to 60. Abulfeda gives the Majrá or δρόμος νυχθημέρος, 100 Hashemi miles = 170 of our geographical miles, here too high a rate unless aided by currents. Other Arab authors propose 100,000 paces = 100 Roman or Arab miles = 80 geographical miles. The pilot Theophilus (Ptol. i. 9) rated the day and night run in these seas at 1000 stadia = 100 miles, or two Ptolemeian degrees; the Pelusian geographer having, I have said, reduced the degree to 500 instead of 600 stadia.