Heliometer,[ 34], [234] [237] [238] [240]
Helium, a constituent of prominences, [194] [195] [199];
no absorption by, in solar spectrum, [213]
absorptive action in first-type stars, [376]
bright in gaseous stars, [377] [378] [380]
in Orion nebula, [407]
Helmholtz, gravitational theory of sun-heat, [311]-313
Hencke, discoveries of minor planets,[ 76]
Henderson, parallax of α Centauri,[ 36], [416];
observation of chromosphere,[ 68]
Henry, Paul and Prosper, lunar twilight, [264];
markings on Uranus, [303]
photograph of Saturn, [408]
photographs of nebulæ in the Pleiades, [410] [411]
stellar photography, [413]
plane mirrors, [438]
Herrick and Bradley, duplication of Biela's comet,[ 96]
Herschel, Alexander S., cometary and meteoric orbits, [332]
Herschel, Caroline, her brother's assistant,[ 12];
observation of Encke's comet,[ 90]
Herschel, Colonel, spectrum of prominences, [168];
of reversing layer, [172]
of corona, [174] [Pg 478]