"If I could take my dollie with me," she replied, as she gazed at it tenderly. "And we might go for little boat-rides all around the islands. Do you think there are any little girls on Mars who have beautiful dollies like mine?"
"I really do not know," replied Mary; "but if there are any people living on Mars, I do know they are not like us. We could not live there, as there is not enough air for us to breathe. We would gasp just as that poor fish did the other day, when Uncle Robert hauled it up out of the lake and threw it into the boat. We must have air, and plenty of it, if we want to live."
"So we could not live on Mars, could we, sister?" said Harry.
"It would not be comfortable," replied Mary; "besides, it is not nearly as warm as here. Poor Uncle Robert would nearly freeze during the long winter. He would also find another surprise awaiting him if he went to Mars. Mars is a smaller world than the earth, so everything weighs less."
"Ah! I see," said Harry, clapping his hands with glee. "Uncle would not be so heavy on Mars. How glad he would be to go there! Poor Uncle Robert! He is so heavy he just shakes the house when he walks across the floor. Next time I see him I shall say: 'Go to Mars, Uncle Robert, and see what will happen to you there.' How much would he weigh on Mars?"
"He weighs two hundred and forty pounds here, and would weigh only ninety pounds there, and you would weigh only thirty pounds. So I could pick you up, couch and all, and carry you as easily as Nellie carries her doll in its doll-carriage."
"Then dollie would weigh nothing at all," said Nellie, looking at her doll curiously.
Harry looked puzzled, and after thinking a moment, he said to his sister:
"I cannot see why I would weigh less if I went to Mars."
