It means 'firm floor soil' in Persian. The Gobi desert will be startlingly familiar. At last Murrin arrives at the cultural implications of a nasty terrain peopled by strangers speaking mysterious tongues. Cut off from one another, they weren't exactly welcoming to visitors with ulterior, imperialistic motives. If you control the west, you can't control the east.
States appear and disappear.
It takes a sophisticated system to manage it all. At lecture's end, the students gather their things to return to the frigid outdoors. Murrin smiles benevolently after them. Be charitable to each other. We're in this together.