Henry Van der Weyde (1838–1924) was a Dutch-born English painter and photographer, best known for his photographic portraits of the late 19th century.
 His is considered a photographic pioneer in the use of electric light in photography.
 Amongst his portraits are architect William Burges (c.1880), Alexandra, Princess of Wales,A. E. Housman, actresses Mary Anderson (1887) and Dorothy Dene (1880s), Sir Edwin Arnold, bodybuilder Eugen Sandow (1889) and explorer Fridtjof Nansen (1897).
Charles J. Kleingrothe, born Carl Josef Kleingrothe or Klein-Grothe, known as C. J. Kleingrothe (Krefeld, 1864 - 1925) was a German photographer who since 1889 (?)
 had a studio in Medan, Sumatra at the end of the 19th century and early 20th century.
 In 1891 (?)
 he partnered with the Swedish photographer H. Stafhell for ten years and photographed the landscapes and architecture as well as portraits.
 In 1901, the partnership ended and in 1902 Kleingrothe opened a studio on Kesawan street in downtown Medan and photographed agricultural subjects including tobacco, coffee, tea, rubber and palm oil cultivation, administration and transport.
Baron Adolph de Meyer (1 September 1868 – 6 January 1946) was a photographer famed for his photographic portraits in the early 20th century, many of which depicted celebrities such as Mary Pickford, Rita Lydig, Luisa Casati, Billie Burke, Irene Castle, John Barrymore, Lillian Gish, Ruth St. Denis, King George V of the United Kingdom, and Queen Mary.
 He was also the first official fashion photographer for the American magazine "Vogue", appointed to that position in 1913.
Photographic plates preceded photographic film as a capture medium in photography.
 The light-sensitive emulsion of silver salts was coated on a glass plate, typically thinner than common window glass, instead of a clear plastic film.
 Glass plates were far superior to film for research-quality imaging because they were extremely stable and less likely to bend or distort, especially in large-format frames for wide-field imaging.
 Early plates used the wet collodion process.
 The wet plate process was replaced late in the 19th century by gelatin dry plates. Glass plate photographic material largely faded from the consumer market in the early years of the 20th century, as more convenient and less fragile films were increasingly adopted.
 However, photographic plates were reportedly still being used by one photography business in London until the 1970s, and they were in wide use by the professional astronomical community as late as the 1990s.
 Workshops on the use of glass plate photography as an alternative medium or for artistic use are still being conducted.
Ecology is a new science and considered as an important branch of biological science, having only become prominent during the second half of the 20th century.
 Ecological thought is derivative of established currents in philosophy, particularly from ethics and politics.
 Its history stems all the way back to the 4th century.
 One of the first ecologists whose writings survive may have been Aristotle or perhaps his student, Theophrastus, both of whom had interest in many species of animals and plants.
 Theophrastus described interrelationships between animals and their environment as early as the 4th century BC.
 Ecology developed substantially in the 18th and 19th century.
 It began with Carl Linnaeus and his work with the economy of nature.
 Soon after came Alexander von Humboldt and his work with botanical geography.
 Alfred Russel Wallace and Karl Möbius then contributed with the notion of biocoenosis.
 Eugenius Warming’s work with ecological plant geography led to the founding of ecology as a discipline.
 Charles Darwin’s work also contributed to the science of ecology, and Darwin is often attributed with progressing the discipline more than anyone else in its young history.
 Ecological thought expanded even more in the early 20th century.
 Major contributions included: Eduard Suess’ and Vladimir Vernadsky’s work with the biosphere, Arthur Tansley’s ecosystem, Charles Elton's "Animal Ecology", and Henry Cowles ecological succession.
 Ecology influenced the social sciences and humanities.
 Human ecology began in the early 20th century and it recognized humans as an ecological factor.
 Later James Lovelock advanced views on earth as a macro-organism with the Gaia hypothesis.
 Conservation stemmed from the science of ecology.
 Important figures and movements include Shelford and the ESA, National Environmental Policy act, George Perkins Marsh, Theodore Roosevelt, Stephen A. Forbes, and post-Dust Bowl conservation.
 Later in the 20th century world governments collaborated on man’s effects on the biosphere and Earth’s environment.
Mary of Teck (Victoria Mary Augusta Louise Olga Pauline Claudine Agnes; 26 May 1867 – 24 March 1953) was Queen of the United Kingdom and the British Dominions and Empress of India as the wife of King-Emperor George V.
Ethel Standiford-Mehlingan (1871–1963) was an artist and photographer born in Jackson County, Kentucky, in the late 19th century.
 She studied to be a teacher but instead apprenticed to a photographer.
 By 1901 she owned and operated the Standiford Photographic Studio in Louisville, Kentucky.
 In the early part of the 20th century she experimented with early photographic techniques such as the autochrome Lumiere and photo-viewing devices such as the diascope.
 An example of her early photography is the autochrome Lumiere diascope of two of the children of Eleanor Silliman Belknap Humphrey.
Rockdale, also known as The Robinson/Stirling Place, is a historic home and farm complex located at Fallston, Harford County, Maryland, United States.
 It is a farm developed from the late 18th century through the early 20th century.
 The dwelling is in three parts.
 The east room of the east wing is the earliest section dating from the 18th century.
 The largest or main portion of the dwelling dates from between 1815 and 1830.
 The north wing, a bay centered in the south façade of the second story, and a small conservatory, date from the very early 20th century.
 The main house is five bays in length, two and a half stories, of stone construction, stuccoed and scored.
 The home is surrounded by several outbuildings, trees, and other plantings, and the remains of formal gardens and garden structures developed in the early 20th century.
 It was the residence of William E. Robinson (1860-1935), an entrepreneur in the local canning industry.
Frank William Micklethwaite (1849–1925) was a prominent Canadian photographer, professionally known as F.W. Micklethwaite, whose photographs of Toronto and the Muskoka area form an important and unique photographic record of the province of Ontario's history in the late 19th century and early 20th century.
 Micklethwaite specialized in outside views and landscapes, as well as architectural and commercial photography, and he was one of Toronto's best known photographers.
 His images of Toronto have been credited for making the 19th century streetscapes come alive.
The Photo-Secession was an early 20th century movement that promoted photography as a fine art in general and photographic pictorialism in particular.
 A group of photographers, led by Alfred Stieglitz and F. Holland Day in the early 20th century, held the then controversial viewpoint that what was significant about a photograph was not what was in front of the camera but the manipulation of the image by the artist/photographer to achieve his or her subjective vision.
 The movement helped to raise standards and awareness of art photography.
 The group is the American counterpart to the Linked Ring, an invitation-only British group which seceded from the Royal Photographic Society.

Question: Who was the wife of a photographer famed for his photographic portraits in the early 20th century?
Answer: Mary of Teck