"He was interested in finding the northwest passage from Ushindi," said Samos. "It could mean the opening up of a considerable number of new markets, the enhancement of trade, the discovery of a valuable commercial avenue for the merchandise of the north and the products of the south."

"It might avoid, too, the dangers of shipment upon Thassa," I said, "and provide, as well, a road to conquest and the acquisition of new territory."

"Yes," said Samos. "You think like a warrior," he said.

"But Shaba 's work," I said, "as I understand it demonstrated that no such passage exists."

"Yes," said Samos, "that is a consequence of his expedition. But surely, even if you are not familiar with the role of Bila Huruma in these things, you have heard of the further discoveries of Shaba."

"To the west of Lake Ushindi," I said, "there are floodlands, marshes and bogs, through which a considerable amount of water drains into the lake. With considerable hardship, limiting himself to forty men, and temporarily abandoning all but two boats, which were half dragged and thrust through the marshes eastward, after two months, Shaba reached the western shore of what we now know as Lake Ngao."

"Yes," said Samos.

"It is fully as large as Lake Ushindi, if not larger," I said, "the second of the great equatorial lakes."

"Yes," said Samos.

I conjectured that it must have been a marvelous moment when Shaba and his men, toiling with ropes and poles, wading and shoveling, brought their two craft to the clear vista of vast, deep Lake Ngao. They had returned then, exhausted, to the balance of their party and boats, which had been waiting for them at the eastern shore of Ushindi.

" Shaba then continued the circumnavigation of Lake Ushindi," said Samos. "He charted accurately, for the first time, the entry of the Cartius proper, the subequatorial Cartius, into Ushindi. He then continued west until he reached the six ubarates and the heartland of Bila Huruma."