"We might have done so, only I am afraid you would have become very tired had we attempted it," laughed Uncle Bob. "In addition to optical glass there are still other branches of science that could not go on without glass in its various forms. Take, for instance, electricity. It would not be safe to employ this strange force without the protection of glass barriers to hedge in its dangerous current. Glass, as you probably know, is a non-conductor of electricity, and whenever we wish to confine its power and prevent it from doing harm we place a layer of glass between it and the thing to be protected. The glass checks the progress of the current. In all chemical laboratories, too, no end of glass test-tubes, thermometers, and crucibles are in demand for furthering research work. Science would be greatly hampered in its usefulness had it not recourse to glass in its manifold forms." "What a wonderful material it is!" ejaculated Jean. "I never shall see anything made of glass again without thinking of all it does for us." "Be grateful, too, Jean, to the men who have discovered how to use it," replied Mr. Cabot gravely. "Certainly our mariners many a time owe their safety to just such warning beacons as the one ahead. We must ask the captain what light that is. Just think--to-morrow morning we shall wake up in Boston harbor and be at home again." A hush fell on the party. "I shall be dreadfully sorry to have Miss Cartright leave us and go to New York; sha'n't you, Uncle Bob?" said Jean at last, slipping her hand into that of the older woman who stood beside her. "Wouldn't it be nice, Miss Cartright, if you lived in Boston? Then I'd see you all the time--at least I would when I wasn't in Pittsburgh, and then Uncle Bob could see you, and that would be almost as good." "Almost," echoed Uncle Bob. "But you are coming to New York to see me some time, Jean dear," the girl said with her eyes far on the horizon. "You know your uncle has promised that when you go to Pittsburgh both you and Giusippe are to stop and visit me for a few days." "Yes, I have not forgotten; it will be lovely, too," replied Jean. "Still that is not like having you live where you can dress dolls all the time. Why don't you move to Boston? I am sure you would like it. We have the loveliest squirrels on the Common!" Everybody laughed. "I have been trying to tell Miss Cartright what a very nice place Boston is to live in," added Mr. Cabot softly. "Well, we all will keep on telling her, and then maybe she'll be convinced," Jean declared. So they parted for the night.