Walt whitman. ca. 1860-65. Grey eyes. No description about his eye colour found on the web. Contemporary paintings have shown blue, grey versions. By Mathew Brady.

Mahatma Gandhi receives a donation in a train compartment. Acharya Kripalani and Radhakrishna Bajaj are looking through the window, 1940.

Millard Fillmore. Circa 1855-1865. By Mathew B. Brady.

Herbert Hoover, head-and-shoulders portrait, facing slightly right. Year 1928. By Underwood & Underwood, Washington.

Susie King Taylor. c. 1902

Charles Darwin. circa 1881. Photographed by Herbert Rose Barraud.

Alfred Tennyson. His eyes are downcast and looking slightly to the right. He has a full beard and mustache. 1866. Photographed by Julia Margaret Cameron.

Portrait of Chandrasekhara V. Raman. Circa 1930. Photograph by A. Bortzells Tryckeri, courtesy of AIP Emilio Segrè Visual Archives, W. F. Meggers Gallery of Nobel Laureates Collection.

Charles Robert Richet. Unknown year. Judging by appearance it should be around 1890-1900. Unknown photographer.

Photograph shows Samuel Langhorne Clemens (Mark Twain), head and shoulders portrait, facing right. ca. 20th May 1907

Sir Charles Scott Sherrington. Circa 1920-25. By Bain News Service.

Portrait of Edvard Grieg. Year: 1890 to 1907. By: H. Abel.

Photograph of Sarvepalli Radhakrishnan presented to First Lady Jacqueline Kennedy in 1962. Circa March 1962.

Theodore Roosevelt By Pach Brothers c 1904.

Portrait of author Ernest Hemingway posing with sailfish: Key West, Florida. 1940 (circa)

Gustav Mahler. Year: c1909. Photoprint copyrighted by A. Dupont, N.Y.

Gandhi writing, August 1942.

Portrait of Robert Herman Koch. Year circa 1908.

Giacomo Puccini smoking a cigarette wearing an overcoat and a bowler. 8th April 1908. By A. Dupont.

Chester A. Arthur. Circa between 1870 and 1880.

Thomas Edison in lab with "Edison Effect" bulbs. Year: 1919. Location: West Orange, New Jersey.

A portrait of Henrik Pontoppidan. Year: Circa 1888-1913. By Frederik Riise.

Messing with Photoshop

Lewis Powell (aka Lewis Payne), in sweater, seated and manacled, one of the conspirators in the Abraham Lincoln assassination. This photograph has background of dark metal, and was presumably taken on U.S.S. Saugus, where he was for a time confined. Washington Navy Yard, District of Columbia. 27 April 1865. By Alexander Gardner.

Daguerreotype of John Tyler, tenth president of the United States. circa 1845-50. By Edwards & Anthony.

Dr. Bernardo Houssay working at the laboratory. Year 1949. By J.W. McGuire.

Charles Sumner. c. 1860-65

Charles Sumner. c. 1870. Taken in Lowell, Massachusetts (probably)

Walt Whitman. ca. 1862. Grey eyes. No description about his eye colour found on the web. Contemporary paintings have shown blue, grey versions. By Mathew Brady.

P.T. Barnum. Created between 1855 and 1865. Photographed by Mathew Brady.

original photo, see colourisation

www.flickr.com/photos/karhil/474358294

Portrait of Swedish author August Strindberg. Year: 1912. Photographer: Sven Åsberg. Location: Stockholm.

Bjørnstjerne Bjørnson, 1903. By Karl Anderson.

original photo, see colourisation

www.flickr.com/photos/karhil/474376383/

Millard Fillmore. Circa 1855-1865. By Mathew B. Brady.

Ida M. Tarbell, head-and-shoulders portrait, facing front. c1904.

Franklin D. Roosevelt. about 1932. Photographer- Vincenzo Laviosa

Arthur Schopenhauer March 1859. By Johann Schäfer.

Chester Alan Arthur. Circa 1880. By Abraham Bogardus.

Portrait of George B. McClellan. Circa 1860-65. Most likely 1861. By Mathew Brady.

Ulysses S. Grant 22nd April 1865, Philadelphia, Pennsylvania. By Frederick Gutekunst. The black armband hanging from his sleeve may be a mourning band for President Abraham Lincoln who was assassinated on April 14, 1865. Probably taken while Lincoln's courtege traveled through Philadelphia.

Fyodor Dostoyevsky, 9 June 1880. Photographed by Mikhail Mikhailovich Panov.

Portrait of Frederick Douglass. Circa 1879. By George Kendall Warren.

Portrait of Thomas Hardy, 1889. Woodburytype. By Herbert Rose Barraud.

Alfred Werner. Circa 1915. Unknown photographer.

Phineas T. Barnum, attributed to Mathew Brady Studio, c. 1860-1870, glass plate collodion negative.

President Lincoln & General George B. McClellan in the general's tent at Antietam, 3rd October 1862. Dissatisfied with General McClellan’s non-responsiveness after Antietam Abraham Lincoln went out to Maryland in October to meet with him. McClellan had a habit of making the commander in chief come to him, which Lincoln tolerated but also noted as a sign of the officer’s arrogance. Photographed by Alexander Gardner.

Portrait of Arthur Stanley Eddington. Prior to 1945. Photograph by Transocean (Photographic company, Berlin).