sun-spots

The amount of, and presence of, sun-spots is the crucial factor.

On Thursday, the Legg report will be published along with... 2009

Afterwards, in a wood, he spread a rug for her, and she lay in a nest of sun-spots.

Maurice Guest 2003

In certain regions of the photosphere several dark patches are usually visible, which are called 'sun-spots.'

The Astronomy of Milton's 'Paradise Lost' Thomas Nathaniel Orchard

The latter are usually found in the vicinity of sun-spots, and, besides hydrogen, contain the vapours of various metals.

The Astronomy of Milton's 'Paradise Lost' Thomas Nathaniel Orchard

It would therefore appear that sun-spots have a pronounced effect upon magnetic terrestrial phenomena, but how this is produced remains unknown.

The Astronomy of Milton's 'Paradise Lost' Thomas Nathaniel Orchard

The duration of sun-spots is subject to considerable variation; some last for weeks or months, and others for a few days or hours.

The Astronomy of Milton's 'Paradise Lost' Thomas Nathaniel Orchard

Besides sun-spots, there are seen on the solar disc bright flocculent streaks or ridges of luminous matter called _faculæ_; they are found over the whole surface of the Sun, but are most numerous near the limb and in the immediate vicinity of the spots.

The Astronomy of Milton's 'Paradise Lost' Thomas Nathaniel Orchard

By long observation it has been ascertained that sun-spots increase and diminish in number with periodical regularity, and that a maximum sun-spot period occurs at the end of each eleven years.

The Astronomy of Milton's 'Paradise Lost' Thomas Nathaniel Orchard

Jane H. wants to know about the mongoose: what kind of snakes it kills; about sun-spots and their influence on the seasons.

The Great Round World and What Is Going On In It, Vol. 2, No. 5, February 3, 1898 A Weekly Magazine for Boys and Girls Various

Nearly all observers have arrived at the conclusion that sun-spots are depressions or cavities in the photosphere, but considerable difference of opinion exists as to how they are formed.

The Astronomy of Milton's 'Paradise Lost' Thomas Nathaniel Orchard