Parallax

In astronomy, the difference in direction of a celestial object as seen by an observer from two widely separated points. The measurement of parallax is used directly to find the distance of the body from the Earth (geocentric parallax) and from the Sun (heliocentric parallax). The two positions of the observer and the position of the object form a triangle; if the base

Abbeville

Pet Shop Boys, The

Formed in London in 1981 by vocalist Tennant (then a writer for the music magazine Smash Hits) and keyboardist Lowe, the Pet Shop

Computers, The Difference Engine

Charles Babbage was an English mathematician and inventor: he invented the cowcatcher, reformed the British postal system, and was a pioneer in the fields of operations research and actuarial science. It was Babbage who first suggested that the weather of years past could be read from tree rings. He also had a lifelong fascination with keys, ciphers, and mechanical

Sarapul

City and centre of Sarapul rayon (sector) of Udmurtia, in western Russia. It is a port on the Kama River. Founded in the 16th century as a Russian stronghold on the trade route to Siberia, it was attacked by Pugachov rebels in 1774; it was chartered in 1780. Sarapul's industries produce machine tools, radios, footwear, and foods. Several technical colleges and an agricultural college

Salamanca

As an important Iberian settlement, it was ravaged by the Carthaginian general Hannibal in 217 BC. A Roman

Maha Maya

According to Buddhist legend, Maha Maya dreamed that a white elephant with six tusks entered her right side, which was interpreted to mean that she had conceived a child who would become either a world ruler or a buddha. After 10 lunar months, feeling that the time of birth was near, she went to the Lumbini

China, Western challenge, 1839–60

The opium question, the direct cause of the first Sino-British clash in the 19th century, began with a late 18th-century British attempt to counterbalance their unfavourable China trade with traffic in Indian opium. After monopolizing the opium trade in 1779, the East India Company's government began to sell the drug at auction to private British traders in India, who shipped

Durand-ruel, Paul

Durand-Ruel began his career in his father's art gallery, which he inherited in 1865. At the outset he concentrated on buying the work of Barbizon artists—particularly Camille Corot, Charles-François Daubigny, and Jules Dupré—and for

Strasbourg

Besides its traditional role as the chief city of Alsace, Strasbourg is also the seat of the Council of Europe, an episcopal see, a university town, and an international communications centre. The river port, which lies east of the