The rise of air temperatures near Earth's surface over the past century is known as global warming. Earth has experienced periods of gradual wanning and cooling throughout its existence due to natural causes, such as volcanic eruptions and variations in the un 's output. However, scientists have attributed …
Earlyyears. Francis was the son of Charles de Valois-Orleans, comte d'Angoulerne, and Louise of Savoy. On the accession of his cousin Louis XII in 1498, Francis became heir presumptive and was given the Duchy of Valois. With his sister Marguerite, he was raised by his mother, who had been wid• owed at the age…
Estonia, country in northeastern Europe, the northernmost of the three Baltic states. Estonia's area includes some 1,500 islands and islets; the two largest of these islands, Saaremaa and Hiiurnaa, are off mainland Estonia's west coast.
Estonia has been dominated by foreign powers through much of its…
Daigo, in full DAJGO TENNO, personal name ATSUKIMJ (b. Feb. 6, 885; Kyoto-e-d. Oct. 23, 930, Kyoto), 60th emperor of Japan. He was unsuccess ful in continuing his father's policy of limiting the power of the important Fujiwara family, which dominated the Japanese government from 857 to 1160. The son of the emperor Uda, he ascended the t…
Centipedes generally remain under stones, bark, and ground litter by day. At night they hunt for and capture other small invertebrates. They move rapidly on from 14 to 177 pairs oflegs and have one pair of long, many-jointed antennae and a pair of jawlike, venomous claws just behind the head. The 25-mm ( 1-inch)-long …
azide, any of a class of chemical compounds containing three nitrogen atoms as a group, represented as (-N3). Azides are considered as derived from hydrazoic acid (HN3), an inorganic salt such as sodium azide (NaN3), or an organic derivative in which the hydrogen atom of hydrazoic acid is replaced by a hy…
a cappella (Italian: "in the church style"), performance ofa polyphonic (multipart) musical work by unaccompanied voices. Originally referring to sacred choral music, the term now refers to secular music as well.The a cappella style arose about the time of the composer Josquin des Prez, in the late 15th century, and reached preemine…