CHAPTER XXXIV.
the author's further contributions to human knowledge.
Glaciers—Uniform Postage—Weight of the Bristol Bags—Parcel Post—Plan for transmitting Letters along Aerial Wires—Cost of Verification is part of Price—Sir Rowland Hill—Submarine Navigation—Difference Engine—Analytical Engine—Cause of Magnetic and Electric Rotations—Mechanical Notation—Occulting Lights—Semi-occultation may determine Distances—Distinction of Lighthouses numerically—Application from the United States—Proposed Voyage—Loss of the Ship and Mr. Reid—Congress of Naval Officers at Brussels in 1853—My Portable Occulting Light exhibited—Night Signals—Sun Signals—Solar Occulting Lights—Afterwards used at Sebastopol—Numerical Signals applicable to all Dictionaries—Zenith Light Signals—Telegraph for Ships on Shore— Greenwich Time Signals—Theory of Isothermal Surfaces to account for the Geological Facts of the successive Uprising and Depression of various parts of the Earth's Surface—Games of Skill—Tit-tat-to—Exhibitions—Problem of the Three Magnetic Bodies.
Of Glaciers.
Much has been written upon the subject of glaciers. The view which I took of the question on my first acquaintance with them still seems to me to afford a sufficient explanation of the phenomena. It is probable that I may have been anticipated in it by Saussure and others; but, having no time to inquire into its history, I shall give a very brief statement of those views.
The greater part of the material which ultimately constitutes a glacier arises from the rain falling and the snow deposited in the higher portions of mountain ranges, which
