Soil is a mixture of organic matter, gases and organisms that together support life. Earth's body of soil, called the pedosphere, has four important functions: as a medium for plant growth as a means of water storage and purification as a modifier of Earth's atmosphere as a habitat for organismsAll of these functions, in their turn, modify the soil; the pedosphere interfaces with the lithosphere, the hydrosphere, the atmosphere, the biosphere. The term pedolith, used to refer to the soil, translates to ground stone in the sense "fundamental stone". Soil consists of a solid phase of minerals and organic matter, as well as a porous phase that holds gases and water. Accordingly, soil scientists can envisage soils as a three-state system of solids and gases. Soil is a product of several factors: the influence of climate, relief and the soil's parent materials interacting over time, it continually undergoes development by way of numerous physical and biological processes, which include weathering with associated erosion.

Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem. Most soils have a dry bulk density between 1.1 and 1.6 g/cm3, while the soil particle density is much higher, in the range of 2.6 to 2.7 g/cm3. Little of the soil of planet Earth is older than the Pleistocene and none is older than the Cenozoic, although fossilized soils are preserved from as far back as the Archean. Soil science has two basic branches of study: pedology. Edaphology studies the influence of soils on living things. Pedology focuses on the formation and classification of soils in their natural environment. In engineering terms, soil is included in the broader concept of regolith, which includes other loose material that lies above the bedrock, as can be found on the Moon and on other celestial objects as well. Soil is commonly referred to as earth or dirt. Soil is a major component of the Earth's ecosystem; the world's ecosystems are impacted in far-reaching ways by the processes carried out in the soil, from ozone depletion and global warming to rainforest destruction and water pollution.

With respect to Earth's carbon cycle, soil is an important carbon reservoir, it is one of the most reactive to human disturbance and climate change. As the planet warms, it has been predicted that soils will add carbon dioxide to the atmosphere due to increased biological activity at higher temperatures, a positive feedback; this prediction has, been questioned on consideration of more recent knowledge on soil carbon turnover. Soil acts as an engineering medium, a habitat for soil organisms, a recycling system for nutrients and organic wastes, a regulator of water quality, a modifier of atmospheric composition, a medium for plant growth, making it a critically important provider of ecosystem services. Since soil has a tremendous range of available niches and habitats, it contains most of the Earth's genetic diversity. A gram of soil can contain billions of organisms, belonging to thousands of species microbial and still unexplored. Soil has a mean prokaryotic density of 108 organisms per gram, whereas the ocean has no more than 107 prokaryotic organisms per milliliter of seawater.

Organic carbon held in soil is returned to the atmosphere through the process of respiration carried out by heterotrophic organisms, but a substantial part is retained in the soil in the form of soil organic matter. Since plant roots need oxygen, ventilation is an important characteristic of soil; this ventilation can be accomplished via networks of interconnected soil pores, which absorb and hold rainwater making it available for uptake by plants. Since plants require a nearly continuous supply of water, but most regions receive sporadic rainfall, the water-holding capacity of soils is vital for plant survival. Soils can remove impurities, kill disease agents, degrade contaminants, this latter property being called natural attenuation. Soils maintain a net absorption of oxygen and methane and undergo a net release of carbon dioxide and nitrous oxide. Soils offer plants physical support, water, temperature moderation and protection from toxins. Soils provide available nutrients to plants and animals by converting dead organic matter into various nutrient forms.

A typical soil is about 50% solids, 50% voids of which half is occupied by water and half by gas. The percent soil mineral and organic content can be treated as a constant, while the percent soil water and gas content is considered variable whereby a rise in one is balanced by a reduction in the other; the pore space allows for the infiltration and movement of air and water, both of which are critical for life existing in soil. Compaction, a common problem with soils, reduces this space, preventing air and water from reaching plant roots and soil organisms. Given sufficient time, an undifferentiated soil will evolve a soil profile which consists of two or more layers, referred to as soil horizons, that differ in one or more properties such as in their texture, density, consistency, temperature and reactivity; the horizons differ in thickness and generally

George R. Bidwell was a pioneering bicycle salesman and manufacturer. Active in politics as a Republican, from July 14, 1897 to April 3, 1902, he was Collector of the Port of New York. George Rogers Bidwell was born in Buffalo, New York on November 8, 1858, his father Charles S. Bidwell was a prominent Buffalo shipbuilder, his grandfather Benjamin Bidwell a shipwright, had constructed several ships for Matthew C. Perry's fleet during the War of 1812. Bidwell was educated in the public schools of Buffalo before beginning his career in bicycle sales and manufacturing. Bidwell saw his first bicycle at the 1876 Centennial Exposition in Philadelphia and soon bought one for himself. After becoming a proficient bike rider and mechanic, Bidwell inquired to Albert Augustus Pope, a prominent bicycle manufacturer, about becoming a salesman. Pope told Bidwell about his new Columbia bicycles, one of which Bidwell promptly ordered so he could study its design and workings. After being brought into Pope's organization, Bidwell proved to be a successful salesman, Pope promoted him to superintendent of agencies, responsible for supervising the retail locations and franchises that sold the Pope company's products.

In 1880, Bidwell became one of the charter members of the newly-formed League of American Wheelmen. In 1881, Bidwell acceded to Pope's request that he move to New York City to take a sales position at E. I. Horsman's sporting goods store, which Pope hoped would result in increased sales. At a conference of the League of American Wheelmen, Bidwell saw a modern safety bicycle, a Rover designed by John Kemp Starley. Bidwell saw that the safety would replace the Penny-farthing or "ordinary" bicycle with a high front wheel, the industry standard, recommended that Pope start production of safeties, but Pope refused. Bidwell left Pope to start his own corporation, the George R. Bidwell Company, which made safeties and conducted research and development on bicycle design and function. In 1890, Bidwell's research and development let him to become the first American bicycle maker to use pneumatic tires, he lost a lawsuit that accused him of patent infringement for using pneumatic tires, but won an 1892 appeal of the original ruling against him.

Bidwell lost so much money fighting the lawsuit that he needed to acquire outside investors, which he was unable to find. His company went into receivership, he ceased making pneumatic tires, but kept the company operating until his appointment as Collector; as a member of the League of American Wheelmen, Bidwell had lobbied for laws protecting cyclists. In 1894, Bidwell became secretary of the New York County Republican Committee, served for two years. Afterwards, Bidwell took over Republican operations in New York City's Nineteenth Assembly District. In 1897, Bidwell was appointed as Collector of the Port of New York by President William McKinley. Prior to the adoption of the Sixteenth Amendment, customs duties and excise taxes were the primary sources of US federal government revenue, as the largest port in the United States at the time, the Port of New York was therefore the single most important source of federal government income; these factors led the office of Collector of the Port of New York to be described as "the prize plum of Federal patronage not only in this State but in the country, outside of positions in the Cabinet."In 1901, new President Theodore Roosevelt decided to replace Bidwell with New York State Senator Nevada N. Stranahan, against the wishes of Senator Thomas C.

Platt. Bidwell's term in office ended when Stranahan was confirmed in April 1902. After a career in bicycle manufacturing, Bidwell turned his interests to the automobile and established a factory in Pottstown, Pennsylvania for making truck engines. During World War I, Bidwell converted his Pottstown factory to the manufacture of artillery shells. Bidwell died in Brightwaters, New York on March 16, 1948. Bidwell's papers are part of the collections of the Hofstra University Library

Anne Kerr, Lady Kerr was the second wife of Sir John Kerr, Governor-General of Australia 1974-77. They were married during his term of office. Anne Dorothy Taggart was born in 1914, she was known as Nancy to her friends. She was an honours graduate from the University of Sydney. In 1935 she was awarded a French Government travelling scholarship and gained her Master of Arts from the Sorbonne, Paris, she appeared as an official French-English interpreter at more than 30 international conferences over ten years, including Colombo Plan meetings. On one occasion she interpreted for Jawaharlal Nehru at a United Nations human rights seminar in New Delhi, she was fluent in German. In 1941 she married Hugh Walker Robson QC, a barrister, appointed to the bench in 1970, he was Chairman of the Court of Quarter Sessions. They had a daughter. At one time he had made a bid for Liberal Party preselection for the federal seat of Warringah. After the end of World War II, she acted as an interpreter for the Department of External Affairs for visiting French delegations.

During 1963 she taught French at North Sydney Boys High School in Sydney. In 1966 she was the first Australian to become a member of the International Association of Conference Interpreters, her marriage to Robson was dissolved in early 1975. It was reported that "strings had been pulled" to ensure her quick divorce from Robson and an avoidance of publicity. On 29 April 1975, in the Scots Kirk, she married the Governor-General, Sir John Kerr, becoming the second Lady Kerr; as Lady Kerr, she forged a formidable reputation for snobbery: in private, Gough Whitlam called her'Fancy Nancy'. He once corrected her French on a menu, which led Margaret Whitlam to say, only half jokingly, that he had sealed his fate by it. After his dismissal, Whitlam referred to her as "the Lady Macbeth of Yarralumla", she insisted on being addressed'Her Excellency', reinstated the requirement for women to curtsy to her, which Lady Kerr had dispensed with. A memorandum by Sir Paul Hasluck, which recorded a conversation with the Queen's Private Secretary Sir Martin Charteris, alleged the Palace's disillusionment with the couple, belief that "the Kerrs, Lady Kerr, were ‘very greedy’ ".

She was privy to her husband's thoughts and anxieties as the 1975 constitutional crisis developed, but in his autobiography Matters for Judgement Sir John Kerr denied she had either dissuaded him from warning the Prime Minister Gough Whitlam that he was going to dismiss him, or that she herself had a political axe to grind. However, Paul Kelly claims that she was shown the draft dismissal letter on the morning of 11 November, that the sentence "It is for the people now to decide the issue, which the two leaders have failed to decide" was added at her suggestion; the Kerrs moved to England in 1977 after the widespread public criticism of his acceptance of the ambassadorship to UNESCO, a post he was forced to relinquish before taking it up. Her memoirs, Lanterns Over Pinchgut, describe her extensive international experience. Lady Kerr died in 1997 after a long battle with cancer, she was survived by her two children and four grandchildren and is buried beside her husband at Macquarie Park Cemetery and Crematorium.

Spouse of the Governor-General of Australia Brilliant mind and charming manner, Norman Abjorensen, Canberra Times, 20 September 1997 Obituary: Lady Kerr, Sydney Morning Herald, 20 September 1997. National Library of Australia: Hugh Robson interviewed by John Farquharson in the Law in Australian Society oral history project