- Tycho Brahe, 271;
- on star discs, 277;
- obliquity of earth’s axis, 289;
- circumpolar stars, 366;
- Sirius, 390.
- Tyndall, Professor, on natural constants, 328;
- magnetism of gases, 352;
- precaution in experiments, 431;
- use of imagination, 509;
- on Faraday, 547;
- magnetism, 549, 607;
- scope for discovery, 753.
- Types, of logical conditions, 140, 144;
- of statements, 145;
- classification by, 722.
- U
- Ueberweg’s logic, 6.
- Ultimate statements, 144.
- Undistributed, attribute, 40;
- middle term, 64, 103.
- Undulations, of light, 558;
- analogy in theory of, 635.
- Undulatory theory, 468, 520, 538, 540;
- inconceivability of, 510.
- Unique objects, 728.
- Unit, definition of, 157;
- groups, 167;
- of measurement, 305;
- arcual, 306;
- of time, 307;
- space, 312;
- density, 316;
- mass, 317;
- subsidiary, 320;
Table of Contents
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