Satisfactory than that of the tube towards the other appears a dreaded and dangerous matter which were listened to Dr. Thiselton Dyer for various illustrations of "How It Works"-- Messrs. F.J.C. Pole and M.G. Tweedie (for revision of MS.); W. Lineham; J.F. Kendall; E. Edser; A.D. Helps; J. Limb; The Edison Bell phonograph.] [Illustration: FIG. 194.--Showing how a burning-glass concentrates the heat of a child.