(1807-1873) Swiss-American geologist and naturalist famous for his study of glaciers.

Louis John Rudolph Agassiz

(1807-1873) Swiss-American geologist and naturalist famous for his study of glaciers.

"The dredges on this pattern, used in Britain for ten years after their first introduction, about the year 1838, were usually small and rather heavy, not more than 12 to 15 inches in length, by 4 or 4.5 inches in width at the mouth. Two scrapers, the length of the dredge-frame, and 1.5 to 2 inches wide, were set at an angle of about 110 degrees to the plane of the dredge's mouth, so that when the dredge was gently hauled along it took hold of the ground and secured anything loose on its surface." — Encyclopedia Britannica, 1893

Ball's Naturalists' Dredge

"The dredges on this pattern, used in Britain for ten years after their first introduction, about the…

Frederick Augustus Porter Barnard was an American scientist and educationalist. He was the president of Columbia College from 1864 – 1889.

Frederick Augustus Porter Barnard

Frederick Augustus Porter Barnard was an American scientist and educationalist. He was the president…

American writer and naturalist.

John Burroughs

American writer and naturalist.

(1840-1897) Distinguished American naturalist

E. D. Cope

(1840-1897) Distinguished American naturalist

(1769-1832) Cuvier was a naturalist and devoted to many departments of natural and scientific research.

Georges Cuvier

(1769-1832) Cuvier was a naturalist and devoted to many departments of natural and scientific research.

An English naturalist who established that all species of life have descended over time from common ancestry. He proposed the theory of natural selection and evolution.

Charles Darwin

An English naturalist who established that all species of life have descended over time from common…

(1890-1882) Naturalist known for his theories of Evolution and Natural selection

Charles Robert Darwin

(1890-1882) Naturalist known for his theories of Evolution and Natural selection

James Hutton MD was a Scottish geologist, physician, naturalist, chemist and experimental farmer. He is considered the father of modern geology.

James Hutton, M.D.

James Hutton MD was a Scottish geologist, physician, naturalist, chemist and experimental farmer. He…

(1811-1875) American scientist and naturalist. Created a catalogue of plants and shells found in the vicinity of milwaukee on the west side of Lake Michigan.

Increase A. Lapham

(1811-1875) American scientist and naturalist. Created a catalogue of plants and shells found in the…

(1823-1891) American naturalist and physician

Joseph Leidy

(1823-1891) American naturalist and physician

Great naturalist who announced that brachiopods were not to be classed under mollusks but under worms.

Edward Sylvester Morse

Great naturalist who announced that brachiopods were not to be classed under mollusks but under worms.

(1838-1914) American geologist, naturalist, explorer, and one of the first preservationists.

John Muir

(1838-1914) American geologist, naturalist, explorer, and one of the first preservationists.

John Muir (April 21, 1838 – December 24, 1914) was a Scottish-born American naturalist, author, and early advocate of conservation of U.S. wilderness.

John Muir

John Muir (April 21, 1838 – December 24, 1914) was a Scottish-born American naturalist, author,…

Charles Willson Peale (April 15, 1741 – February 22, 1827) was an American painter, soldier and naturalist.

Charles Wilson Peale

Charles Willson Peale (April 15, 1741 – February 22, 1827) was an American painter, soldier and…

"Close to the place where the dredge is emptied there ought to be a tub about 2 feet in diameter and 20 inches deep, provided with a set of sieves so arranged that the lowest sieve fits freel within the bottom of the tub, and the three remaining sieves fit freely within one another. Each sieve has a pair of iron handles through which the hand can pass easily, and the handles of the largest sieve are made long, so that the whole nest can be lifted without stooping or putting the arms into the water." — Encyclopedia Britannica, 1893

Set of Sieves

"Close to the place where the dredge is emptied there ought to be a tub about 2 feet in diameter and…

Henry David Thoreau (born David Henry Thoreau; July 12, 1817 – May 6, 1862) was an American author, naturalist, transcendentalist, tax resister, development critic, sage writer and philosopher. He is best known for his book Walden, a reflection upon simple living in natural surroundings, and his essay, Civil Disobedience, an argument for individual resistance to civil government in moral opposition to an unjust state.

Henry David Thoreau

Henry David Thoreau (born David Henry Thoreau; July 12, 1817 – May 6, 1862) was an American author,…

Blooming tulips featuring large flowers.

Darwin Tulip

Blooming tulips featuring large flowers.

(1823-1913) English naturalist

Alfred Russel Wallace

(1823-1913) English naturalist