He regarded Billy doubtfully.
“I’m sure I couldn’t,” said Billy. “Besides, what’s the need of going at all?”
“Oh, I really must go! A foolish Spring Tide broke one of the tropics the other day, and if the other gets broken there will be nothing to hold the Equator down but the meridians, and you know they’re very fragile.”
Billy didn’t know that, but he nodded intelligently. It is always best to pretend to know more about geography than you really do.
“We’ll be back in time for dinner,” continued Nimbus; “that is, if I don’t have to fasten up the tides again.”
“Why,” said Billy, “you don’t mean to say you have to fasten the tides?”
“Certainly!” replied Nimbus. “You know the tides are always trying to put out the Moon, and they go chasing around the Earth after her night and day. Of course the shore stops them after a while and drives them back, and that’s what makes them high and low. They’re high when they run up and try to wash over the shore, and low when the shore drives them back again. But to keep them from going too far we tie them down with meridians. That’s why they call them tides. Each one is tied, don’t you see?”
“Gracious!” exclaimed Billy. “I hope they can’t get untied and put the Moon out.”
“Oh, they won’t,” Nimbus assured him, “while I’m watching them! Sometimes they sneak up on her out of the ocean in little drops that we call mist, but the Sun always catches them at it, and sends them scurrying down in rain again.”
“I almost believe I’ll go,” said Billy, “if you’re sure we can be back in time.”