HIP-KNOB

hip-knob, in architecture, the finial on the hip of a roof, between the barge-boards of a gable. hipparchus (fl. 146-126 b.c.), greek astronomer, was born at nicaea in bithynia early in the 2nd century b.c. he observed in the island of rhodes probably from 161, certainly from 146 until about 126 b.c., and made the capital discovery of the precession of the equinoxes in 130 (see astronomy: _history_). the outburst of a new star in 134 b.c. is stated by pliny (_hist. nat._ ii. 26) to have prompted the preparation of his catalogue of 1080 stars, substantially embodied in ptolemy's _almagest_. hipparchus founded trigonometry, and compiled the first table of chords. scientific geography originated with his invention of the method of fixing terrestrial positions by circles of latitude and longitude. there can be little doubt that the fundamental part of his astronomical knowledge was derived from chaldaea. none of his many works has survived except a commentary on the _phaenomena_ of aratus and eudoxus, published by p. victorius at florence in 1567, and included by d. petavius in his _uranologium_ (paris, 1630). a new edition was published by carolus manitius (leipzig, 1894). see j. b. j. delambre, _histoire de l'astronomie ancienne_, i. 173; p. tannery, _recherches sur l'histoire de l'astr. ancienne_, p. 130; a. berry, _hist. of astronomy_, pp. 40-61; m. marie, _hist. des sciences_, i. 207; g. cornewall lewis, _astronomy of the ancients_, p. 207; r. grant, _hist. of phys. astronomy_, pp. 318, 437; f. boll, _sphaera_, p. 61 (leipzig, 1903); r. wolf, _geschichte der astronomie_, p. 45; j. f. montucla, _hist. des mathematiques_, t. i. p. 257; j. a. schmidt, _variorum philosophicorum decas_, cap. i. (jenae, 1691). (a. m. c.)