Tidal friction, effects on moon's rotation, [271] [272] [318];
month lengthened by, [316] [318]
influence on planets, [319]-322
on development of binary systems, [420]
Tietjen, asteroidal orbits, [284]
Tisserand, capture of comets,[ 98];
lunar acceleration, [273]
revolutions of Neptune's satellite, [305]
stationary radiants, [341]
perturbations of Algol, [391]
director of Paris Observatory, [414]
Titius, law of planetary intervals,[ 71],[ 72],[ 85]
Todd, eclipse of 1887 [185];
solar distance, [236] [241]
trans-Neptunian planet, [306]
Tornaghi, halo round Venus, [254]
Transit instrument, [120]
Trépied, reversal of Fraunhofer spectrum, [172]
Troughton, method of graduation, [122]
Trouvelot, veiled spots, [148];
chromosphere in 1878 [175]
intra-Mercurian planets, [181] [250]
observations of prominences, [184] [196] [204]
of Mercury, [245] [247]
rotation of Venus, [252]
red spot on Jupiter, [296]