"Ah!" murmured Miette, disappointed; and, as Monsieur Roger kept silent, she added, "What is density?"
"It would take a long time to explain."
"Tell me all the same."
Monsieur Roger saw at this moment that Paul was beckoning to Miette to insist.
"Goodness!" said he, smiling at Paul; "Miss Miette was right just now. It is you that wish me to continue the questions!"
[CHAPTER XIII.]
WHY LEAD IS HEAVIER THAN CORK.
Monsieur Roger continued in these words: