I.L.G. Rice must, however, bear in mind that expansion is thoroughly understood by scientists, and that Dr. Moissan was not doing the rough work of a foundry, but conducting a most delicate experiment, in which he brought into play all the scientific knowledge available. DEAR EDITOR:--I have been thinking that I would write you and tell you how much I like THE GREAT ROUND WORLD. It interests me very much. I have looked for salt in the streets, but have not seen any. It was funny that the bottle that Mr. McCoy threw into the water made such a journey. I must stop now, but I still remain, Your affectionate reader, NEW YORK CITY. JOHN F. RUSSELL, JR. DEAR EDITOR:--I am very much pleased with your book, THE GREAT ROUND WORLD. My father wrote you to-day. I am very much interested in it. I want to ask you a few questions. Can you tell me where you get your news? I see you say that Maceo was shot, after all. Do you think United States will declare war with Spain? Could you send me a copy of THE GREAT ROUND WORLD about the time the news of Maceo's death was first heard of, if you have a spare one? I must close now. Please direct the letter to NORTH ADAMS, MASS. FRED S. HALL. DEAR EDITOR:--Our teacher has been receiving all of THE GREAT ROUND WORLD papers, and she reads to us every morning. We like the paper ever so much, and have learned a great deal about both the Cuban war and our government. She also read us the little note you had printed in the back, saying you would answer (and be glad to) any question we might ask. We pupils do not understand about the new platform at the end of Brooklyn Bridge, and I am going to ask a few questions. Will the platform carry you down as well as up? How many will it carry? About how large is it? Is there more than one? If so, please tell me how many. From your friend, CHEYENNE, WYO. ELSIE K. (age 11). DEAR ELSIE: In reply to your letter about the Brooklyn Bridge. It is only arranged to save people climbing up-stairs. It is easy enough to go down-stairs, but it is the climbing up that people dislike, and the new elevator is to save this trouble. It will take up three thousand passengers an hour, and if it is the success it promises to be, six of these lazy-man's staircases will be put into use. It is the same size as the staircase of which it is to take the place. =School Books Wanted= The following school books will be taken in exchange for subscriptions for "Great Round World" at prices named.