He was Lieutenant Calder of the Engineers.

Youth, however, in this instance had no optimism wherewith to challenge Colonel Dawson.
"He left Halfa eight weeks ago, eh ?" he said gloomily.
"Eight weeks to-day," replied the colonel.
It was the third officer, a tall, spare, long-necked major of the Army Service Corps, who alone hazarded a cheerful prophecy.
"It's early days to conclude Durrance has got scuppered," said he.

"One knows Durrance.

Give him a camp-fire in the desert, and a couple of sheiks to sit round it with him, and he'll buck to them for a month and never feel bored at the end.

While here there are letters, and there's an office, and there's a desk in the office and everything he loathes and can't do with.