"Encyclopedia Britannica, 11th edition" is a comprehensive encyclopedic work containing well-founded information from various fields of knowledge. Compiled by a team of authors and experts, this encyclopedia represents a great scientific heritage. In "McKinley, William" - "Magnetism, Terrestrial" (Volume 17, Chapter 3) you will find carefully researched articles on a wide range of topics, from a biography of President William McKinley to terms and concepts related to the Earth's thermal magnetic behavior . This part of the encyclopedia impresses with its depth of knowledge and breadth of coverage of topics. Raising questions important to world development, it is an indispensable source of information for anyone who wants to deepen their knowledge and broaden their horizons.