Then he went on holiday, ten days, back to his home in Gloucestershire, the country vicarage and the Cotswold hills, where the pick of the old prize fighters came from; and there was much of the prize fighter in Carstairs' composition, perhaps it was in the air.

The Reverend Hugh Carstairs was tall and well built, silver haired and clean shaven; his religion was of the comfortable order; he did not consider it necessary to be miserable in order to be good. He was clean in mind and body, rather sporting and rather intellectual. His good lady was somewhat similar, less sporting and less intellectual, more homely and more pious. The product of the union was six well-grown, healthy Englishmen. Jack was the youngest.

His parents received him with undemonstrative but deep-felt pleasure. Up to the present Jack had been, if not the most prosperous, the least expensive of the six; engineering to him had been more or less compulsory because cheap, or comparatively so. The other five had absorbed large sums in their education, and up to the present made small return on capital invested. Jack didn't gamble or drink expensive drinks; he didn't paint pictures or play any musical instrument. As far as his parents knew he had had no love affairs. He was a very sober young man. His mother said he feared God. His father, that he respected himself. The truth was that he had an ambition to bulk very big at some future date, and so had not the time for indulgence in the ordinary common or garden vices and pastimes.

He kissed his mother and shook hands solemnly with his father.

"I want to take some of your books away with me when I go, guv'nor," he said.

His parents looked at him with approval. "What sort of books?"

"Oh! 'maths.' I find I don't know as much mathematics as I thought I did."

His mother looked somewhat disappointed, his father pleased. The dividends on classics did not pan out very well in his experience.

"I'm working out an idea, you know; rather good thing if it's workable. Want some more 'maths,' to read up the authorities on the subject."

"A patent?"