1874 transit of VenusW
1874 transit of Venus

The 1874 transit of Venus, which took place on 9 December 1874, was the first of the pair of transits of Venus that took place in the 19th century, with the second transit occurring eight years later in 1882. The previous pair of transits had taken place in 1761 and 1769, and the next pair would not take place until 2004 and 2012. As with previous transits, the 1874 transit would provide an opportunity for improved measurements and observations. Numerous expeditions were planned and sent out to observe the transit from locations around the globe, with several countries setting up official committees to organise the planning.

1874 Transit of Venus Expedition to Campbell IslandW
1874 Transit of Venus Expedition to Campbell Island

The 1874 Transit of Venus Expedition to Campbell Island was an astronomical expedition by French scientists to observe the 9 December 1874 transit of Venus on subantarctic Campbell Island in the Southern Ocean some 600 km south of New Zealand. It was one of several such scientific expeditions from various countries sent around the world to observe the rare astronomical event.

1874 Transit of Venus Expedition to HawaiiW
1874 Transit of Venus Expedition to Hawaii

The 1874 Transit of Venus Expedition to Hawaii was an astronomical expedition by British scientists to observe the December 8 transit of Venus at three separate observing sites in the Hawaiian Islands, then known as the Sandwich Islands. It was one of five 1874 transit expeditions organized by George Biddell Airy, Astronomer Royal at the Royal Observatory, Greenwich. The purpose of the expedition was to obtain an accurate estimate of the astronomical unit (AU), the distance from the Earth to the Sun, by measuring solar parallax. Previous efforts to obtain a precise value of an AU in 1769 had been hampered by the black drop effect. There is a collection of papers relating to this expedition at the Cambridge Digital Library.

1874 in birding and ornithologyW
1874 in birding and ornithology

Challenger expeditionW
Challenger expedition

The Challenger expedition of 1872–1876 was a scientific program that made many discoveries to lay the foundation of oceanography. The expedition was named after the naval vessel that undertook the trip, HMS Challenger.

Maxwell's thermodynamic surfaceW
Maxwell's thermodynamic surface

Maxwell’s thermodynamic surface is an 1874 sculpture made by Scottish physicist James Clerk Maxwell (1831–1879). This model provides a three-dimensional space of the various states of a fictitious substance with water-like properties. This plot has coordinates volume (x), entropy (y), and energy (z). It was based on the American scientist Josiah Willard Gibbs’ graphical thermodynamics papers of 1873. The model, in Maxwell's words, allowed "the principal features of known substances [to] be represented on a convenient scale."

Quebra–Quilos revoltW
Quebra–Quilos revolt

The Quebra–Quilos revolt was a three-month-long revolt in opposition to the proposed transition to a metric system. The unrest took place from 31 October 1874 to January 1875 as part of wider anti-government protests.

Solar eclipse of April 16, 1874W
Solar eclipse of April 16, 1874

A total solar eclipse occurred on April 16, 1874. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide.

StereochemistryW
Stereochemistry

Stereochemistry, a subdiscipline of chemistry, involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on stereoisomers, which by definition have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. For this reason, it is also known as 3D chemistry—the prefix "stereo-" means "three-dimensionality".