He sat down on a hatch cover and tried to think of other things.  The sea was beginning to turn blue—­the blue of deep water—­and the sun was shining brightly.  There was a strong wind and a healthful smell of salt in the air.

Still Bob did not appear to care for any of those things.  His own feelings seemed to increase.

“Sitting still is worse than moving around,” he began to think.

Just then Mr. Carr passed the boy.

“What’s the matter?” he asked.  “You look rather white about the gills, messmate.”

“I—­I don’t feel very well,” replied Bob.

“Better go and lie down then.  I guess you’re in for a spell of seasickness.  Mr. Tarbill has already got his.”

Bob thought it would be best to follow the advice.  He went to his berth, and soon he was a very sick boy.  He would have given up all his chances of rounding the Horn—­yes, he would even have sacrificed his share in the rather mythical treasure of Captain Obed—­if he could only have found some place that was not heaving, pitching and tossing.  But the ship rolled on, and the motion seemed to increase rather than diminish.

It was a week before Bob was entirely well.  During that time he stayed in his bunk, but Captain Spark saw to it that the boy was well looked after and doctored with such simple remedies as are used in that common form of illness, which attacks nearly all who first venture upon the sea.

At the end of the week Bob found that he could stand up without feeling his head go buzzing around.  He ventured out on deck, and the salt breeze brought some color into his pale cheeks.

“You sort of look as if you had been drawn through a knothole,” remarked Tom Manton, one of the sailors.

“Yes, old Father Neptune has been playing tricks on him, I reckon,” added Sam Bender, the second mate.

“I feel as if I had been drawn through two knot-holes, one right after the other,” spoke Bob, with an attempt at a smile.

“You’ll soon be all right again now,” comforted Tom.  “Get a little salt horse and sea biscuit down for a foundation, and you can build up on that the finest thing in the way of a meal you ever saw.”

For the first time since his illness Bob could think of food without a shudder.  He really began to feel hungry.  The old sailor proved a good prophet.  Bob began to mend steadily, and in a few days he was as active as ever—­more so, in fact.

“Now’s the time to look for trouble,” remarked Captain Spark to his mate one day.

“Trouble?  How?”

“Bob is himself again.  He’ll be up to some tricks or I’m a Dutchman.  But we must meet him half way.  Give him back some of his own coin.  He’s on this voyage to be cured, and I’m going to do it If I have to keelhaul him.”

“I guess the men will be only too anxious to do their share.  They like Bob, but he mustn’t play too many pranks on them.”