They half filled their three cups from the sea, and put them in the full glare of the sun. Every now and then Tommy ran to them to see hew they were getting on, every time becoming more sceptical of success. There was still a good deal of water in the cups at nightfall; but, as Mary said, that didn't matter much, as they had used up all their tea, none of them liking coffee at night; so they left the cups as they were, to evaporate the rest of the water next day. When the cups were at last dry there was no appreciable sediment, and Tommy with great scorn pronounced the experiment a failure.
"The cups don't hold enough," said Mary. "What we want is a large shallow pan, and as we haven't got one, I'm afraid you'll have to go without salt, Bess."
But a day or two after, Elizabeth discovered a wide shallow depression in a rock a little distance above high-water mark.
"This will do for a pan," she said. "We'll fill it with sea-water with our cups, and keep on filling it up as the water evaporates. Then we'll see, my dears."
They followed this plan for several days, and at last were able to collect a fair quantity of salt.
"It isn't table salt, to be sure," said Elizabeth, looking at the dirty-grey powder, "but it is certainly salt enough for anything, and this quantity will last for a week at least."
"We are getting quite clever," said Mary. "I dare say we shall be able to make quite a lot of things by and by."
During these days they had seen no more signs of inhabitants, and their nervousness partially wore off. They were still careful, however, not to stray far beyond the immediate neighbourhood of their camp, and slept every night in the boat, which they left close to the brink of the sea. They devoted a good deal of time to weaving grass mats for the floor of their hut, but had not as yet plucked up courage to spend a night in it. With the boat as a refuge they felt a certain sense of security, though they admitted, when they talked about it, that it would not really be of any great service if they were attacked; for they could only escape by embarking, and then to drift on the sea out of reach of food was a terrible fate to look forward to.
One day, when Mary had been out to gather bananas, she came back with the news that she had gathered the very last one, so that they were faced with the immediate necessity of finding another food supply.