American Anniversaries: Every Day in the Year, by Philip Robert Dillon, Philip Robert Dillon Publ. Co. (1918). (source)
American National Biography, by American Council of Learned Societies, Oxford University Press.
Asimov's Biographical Encyclopedia of Science and Technology, by Isaac Asimov, 2nd rev ed., Doubleday & Co., (1982)
Biographical Dictionary of the History of Technology, by Day and McNeil. Routledge (1996)
The Cambridge Dictionary of Scientists, by David, Ian, John and Margaret Miller, Cambridge University Press (1996.)
Chamber's Dictionary of Scientists, by A. V. Howard, E.P. Dutton & Co. (1951)
Dictionary of Scientific Biography, American Council of Learned Societies (1981)
Dorling Kindersley website
Dictionary of American Biography, American Council of Learned Societies (1977)
Dictionary of Scientific Biography, American Council of Learned Societies (1981)
Encylopaedia Britannica.
Encyclopedia of World Biography, Gale Research.
Famous First Facts, by Joseph Nathan Kane, H.W. Wilson, 3rd ed. (1981)
Famous First Facts, by Joseph Nathan Kane et. al., H.W. Wilson, 6th edition (2007)
Galenet: Biography Resource Center, Thomson Gale.
Haydn's Dictionary of Dates, by Benjamin Vincent, 23rd ed. (1904)
Isaac Asimov's Book of Science and Nature Quotations, edited by Isaac Asimov and Jason Shulman, publ. Weidenfeld & Nicolson (1988).
Johnson's Universal Cyclopedia: A New Edition, by D. Appleton and A. J. Johnson (1893).
McGraw-Hill Modern Men of Science, in 2 volumes (1966-8)
New York Times archive.
Notable Twentieth-Century Scientists, Gale Research (1995)
Notable Women Scientists, by Pamela Proffitt, Gale Group (2000)
Panati's Extraordinary Origins of Everyday Things, by Charles Panati, Harper & Row, 1989.
Portraits of Men of Eminence, by Lovell Reeve (1864).
Psychologically Speaking: A Book of Quotations, by Kevin Connolly, Blackwell Publishing
Science and Technology Firsts, by Leonard C. Bruno, publ. Gale (1997)
Scribner Encyclopedia of American Lives, Charles Scribner's Sons (1998)
Scientifically Speaking, A Dictionary of Quotations by Carl C. Gaither and Alma E Cavazos-Gaither, publ. Institute of Physics Publishing (2000).
The Harvest of a Quiet Eye: A Selection of Scientific Quotations, selected by Alan L Mackay, Crane, Russak & Co. Inc., NY (1977)
The Shell Book of Firsts, by Parick Robertson, Ebury Press (1974)
The Prize - the Epic Quest for Oil, Money and Power, by Daniel Yergin, Simon & Schuster (1991)
The Times newspaper
The Timetables of Science: A Chronology of the Most Important People and Events in the History of Science by Alexander Hellemans and Bryan Bunch, Simon & Schuster (1991)
The World Almanac Book of Inventions by Valérie-Anne Giscard d'Estaing, Ballantine Books (1985)
World Records in Chemistry by Hans-Jürgen Quadbeck-Seeger, Wiley-VCH (1999)

Allen, David B., picture from obituary, New York Times (31 Mar 1971), 49.
Allison, Fred: ref. for discreditting of magneto-optic effect, A Memoir on the Physical Review: A History of the First Hundred Years, by Paul Hartman, publ. Springer (1994), page 161.
Anguino, Eddie: 21st birthday confirmed by email from Loma Linda Medical Center (20 Nov 2006).
Anonymous, Paper Cut illustration: derivative art by Webmaster using Laughing Tree with kind permission by Denis Wilson from The Nature of Robertson; Tree Stump by Angela Marie from Flickr Commons; Finger Cut by Alvimann from Morguefile.
Barcode: ref. for date given in Century Makers, David Hillman and David Gibbs, p.178, (Welcome Rain, 1999).
Barach, Alvan: picture in New York Times (13 Dec 1977), 51.
Beckett, Allan: picture contributed by family (email 10/24/06).
Bell Photophone: picture (1891) from American Science and Invention, Mitchell Wilson, p. 285
Bertrand, Marcel: picture from Marcel Bertrand (1847-1907), Pierre Termier, Extrait des Annales des mines, 4e livraison de 1908, frontispiece.
Bethe, Hans: picture from Discover, Vol. 20 No. 12 (Dec 1999)
Boisbaudran, Paul-Émile: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 215.
Blanchard, Thomas: picture from Leading American Inventors, by G. Iles, publ. McClelland and Goodchild, Toronto, 1912, p. 104-118. found at Engines of Our Ingenuity, No. 2045.
Blumenbach, Johann Friedrich: Skull collection picture from The Ascent of Man,  J. Bronowski, p. 366.
Boston Philosophical Society: ref for date of meeting in The Last American Puritan: The Life of Increase Mather, 1639-1723, by Michael Garibaldi Hall, pub Wesleyan University Press (1988), page 166.
Bridge, Tay Railway: image from cover of Thomas Bouch: The Builder of the Tay Bridge, by John Rapley.
Bramah, Joseph: picture of his 1778 design of a valve closet which stayed in use into the late 19th century from Encyclopedia of Inventions, Chartwell Books (1976), p.82.
Bramah, Joseph date of hydraulic press patent from Tubular and Other Iron Girder Bridges, Particularly Describing the Britannia and Conway Tubular Bridges, George Drysdale Dempsey, publ. John Weale (1850).
Brown, Barnum: Birthdate from
Burke, James: quote illustration for “Scientists are the true driving force of civilization” is a composite by Ian Ellis using these clips: Pyramid, skyscraper, Skylab, James Burke.
Bussy, Antoine A.B.: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 133.
    Reference for his paper "Mémoire sur le Radical métallique de la Magnésie": Ann. chim. phys. (2) 46, 434-6 (1831).
Butterick, Ebenezer: picture from Historic Homes and Institutions and Genealogical and Personal Memoirs of Worcester County by Ellery Bicknell Crane, The Lewis Publishing Co. (1907)
Canada's Greatest Invention, Canadian Broadcasting Company programme broadcast 3 Jan 2007.
Cassini, Jacques: dates as given on a history web page of the Paris Observatory. Because generations of the Cassini family were astronomers there, those dates have been taken to be definitive. However, Encyclopedia Britannica gives 8 Feb 1677 - 18 April 1756, and the Dictionary of Scientific Biography gives 18 Feb 1677 - 15 Apr 1756. The Paris Observatory history states that Jacques Cassini was injured when his carriage overturned on 15 Apr 1756, and that he died the next day, on the 16th.
Cavendish Laboratory: date of opening from A History of the Cavendish Laboratory 1871-1910, Longmans, Green & Co. (1910), page 13.
CERN: date of adoption of de Broglie recommendation on 12 Dec 1949 from The New York Times, 13 Dec 1949, page 13, article states action took place on closing day of conference; contents page of book History of CERN, vol I, by A. Hermann, et al. gives Conference dates 8-12 Dec 1949.
Chancourtois' Helix: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 204
Chicora Meteorite: ref. Rain of Iron and Ice, John S. Lewis, Helix Books (Addison-Wesley), 1997
Child, Charles Manning: quote cited in Experimental Ecology: Issues and Perspectives, edited by William J Resetarits, Joseph Bernardo, Oxford University Press (2005) p.173.
Colburn, Irving: picture from Toledo: The 20th Century, by Barbara L. Floyd, publ Arcadia Publishing (2005) p. 14.
Comet West: false colour image from Comet Science: The Study of Remnants from the Birth of the Solar System, by Jacques Crovisier, Thérèse Encrenaz, publ. Cambridge University Press (2000) p.41.
Cooper, Irving: Christmas gift reference - The Scribner Encyclopedia of American Lives, Volume 1: 1981-1985. Charles Scribner's Sons, 1998.
Cormack, George: month of death provided by email communication with General Mills.
Cronstedt, Axel: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 147
Crop-dusting: first time event date from "Fighting Insects with Airplanes" by C.R. Nelly and J.S. Houser, National Geographic Magazine, Vol. 41, pages 333-8 (Mar 1922). [Notes: The article is subtitled An Account of the Successful Use of the Flying Machine in Dusting Tall Trees Infested With Leaf-Eating Caterpillars. C.R. Nelly is the entomologist that suggested the idea, so when he wrote the article, he was probably well aware of the correct date for the event. The date, and a mention of that article, is given in Seeds of Change: A History of the Ohio Agricultural Research and Development Center, by Christopher M. Cumo, Wooster Book Co.(1999). However, in the book John Macready - Aviation Pioneer: At the Earth's Ceiling, by Sally Macready Wallace, Sunflower University Press (Sep 1998), the date is given as 31 Aug 1921. The author is the daughter of the pilot, and wrote the book from interviews with her father. All the preceeding sources state lead arsenate as the chemical used. A New York Times article on 8 Jan 1922, p.85, states the use of calcium arsenate as the chemical, which was mentioned earlier in the article as proposed for use on cotton boll weevils.]
Day, Harry: Image courtesy of the Photograph Curator, Indiana University Archives, Bloomington, Ind.
Del Rio, Andrés Manuel. Birth year given by Asimov and Larousse as 1764; given by Weeks as 1765.
Dental drill: patent drawing from On This Day In America, John Wagman.
Rice, Lee R: photo from obituary, Journal of Mammology, Vol 59, No. 3, p.636.
Dines, William: photo courtesy of  Michael Poole,  great-grandson of William Dines.
Diving Suit: information from The Inventive Yankee, Andrea Chesman, editor. Dublin, N.H.: Yankee Publishing Inc., 1989.
Donald, Ian:  Birthdate, 27 Dec 1910, according to an article in the European Journal of Obstetrics and Gynaecology and Reproductive Biology, found courtesy of an email enquiry to Glasgow Royal Infirmary.
Donati's Comet. Reference for further reading: Jay M. Pasachoff, Roberta J.M. Olson & Martha L. Hazen, "The Earliest Comet Photographs: Usherwood, Bond, and Donati 1858," Journal for the History of Astronomy, vol. 27, no. 87 (May 1996): 129-145.
Date of limelight use for surveying fromMemoir of Thomas Drummond, by John Ferguson M'Lennan (1867), p.77.
Duddell, William: photo from Obituary Notices of Fellows Deceased, Proceedings of the Royal Society of London, Series A, Containing Papers of a Mathematical and Physical Character, Vol. 94, No. 664. (Aug. 1, 1918), page U40.
Earth's curvature: from article by William L. Laurence in the New York Times, 31 Dec 1930, p. 1.
Earthquake, Charleston: illustration from "The Stabililty of the Earth," Scribner's Magazine, vol 1, no. 3 (Mar 1887), p. 272.
Elmen, Gustav: photo courtesy of his grand-daughter (received 1/9/06).
Envelope Folding Machine patent for Dr Hawes. Primary source for the 21 Jun date is the original patent image at the U.S.P.T.O. which is taken to be authoritative. It is attributed (by an apparent typo) to a "21 Jan" date in Kane's Famous First Facts, which error has been propagated in many other on-line lists and print media.
Ekeberg, Anders: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 82
Fajans, Kasimir: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 299
Frasch, Herman: picture from Brimstone The Stone That Burns, Williams Haynes, frontispiece.
Fitch, John: picture from American Inventions, Barnes and Noble, p. 11.
Fluorine isolation dates ref. The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 272
Franklin Stove quote: from Benjamin Franklin: A Biography, Ronald W. Clark. Random House, 1983. p. 56.
French Academy of Sciences: date ref. Pendulum: Leon Foucault and the Triumph of Science, by Amir D. Aczel, publ. Simon and Schuster (2003), page 95.
Fulton, Robert: date of steam paddle-boat test on the Seine from Harper's Encyclopedia of United States History from 458 A. D. to 1909, by Benson John Lossing and Woodrow Wilson, publ. Harper (1910) p.393.
Gadolin, Johann: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 230.
Galaxy 8C 1435+635 red shift ref: S. Rawlings et al, 1995, "A radio galaxy at redshift 4.41," Nature, 383, 502; quoted in Isaac Newton Group of Telescopes Annual Report 1995, page 20. (source)
Gas lighting in New York: date from Cradle Days of New York (1609-1825), by Hugh Macatamney, publ. Drew and Lewis (1909), p. 116.
Grubbe, Emile. References for further reading:
    Grubbe EH. The origin and birth of x-ray therapy. Urol Cutaneous Rev 1947 May;51(5):375-9.
    Grubbe EH. X-ray treatment; its introduction to medicine. J Am Inst Homeopath 1946 Dec;39(12):419-22.
Haddon, Alfred: reference "Obituary: Doctor Alfred Cort Haddon, F. R. S.," by C. S. Myers, The Geographical Journal, Vol. 96, No. 3. (Sep., 1940), pp. 230-231.
Hamilton, Joseph: reference for date of his first use of an intravenous radioisotope injection given in his obituary in the New York Times, 20 Feb 1957, p.33. Whereas the newspaper obituary gives date of death as 19 Feb 1957, a University of California In Memoriam (1959) states 18 Feb 1957. Since this was where he was Director of the Crocker Laboratory, part of the Lawrence Berkeley National Laboratory of the Univ. of California, the latter date has been used on this site as probably more correct.
Hargrave, Lawrence: reference for date of flight Omni Magazine, issue dated (?) 1/1/95.
Hatchett, Charles: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 77
Helmholtz, Hermann: date of invention provided by Dr J.E.E. Keunen (pers. com. 6/1/04)
Helvetius, Jean-Adrien: dates of death and honours from Helvetius: His Life and Place in the History of Educational Thought, by Ian Cumming, Routledge (UK, 2003).
Herschel, John: description of crysotype from The Irish Industrial Exhibition of 1853: A Detailed Catalogue of Its Contents, John Sproule, publ. J. McGlashan (1854), page 231.
Highway, Lincoln: facts from The New York Times, 31 Dec 1913, page 12; 26 Jan 1914, page 8; and 5 Apr 1914, page XX8.
Hoagland, Dennis: picture courtesy of the American Society of Plant Biologists.
Hrozny, Bedrich: some information from obituary in Man, Vol. 53. (Jun 1953), page 89.
Hussy, Obed: reaper description from The Marvels of Modern Mechanism and Their Relation to Social Betterment, by Jerome Bruce Crabtree, 1901.
Ice, India: information from The Mechanics' Magazine, Museum, Register, Journal, and Gazette; Publ. J. Cunningham, London (9 Apr 1836) Vol XXV, No. 661, pages 10-12
Johns Hopkins University, picture and information courtesy of JHU Office of Communications and Public Affairs.
Johnson, Edward H: ref. for dates of birth and death Thomas A. Edison, Benefactor of Mankind; The Romantic Life Story of the World's Greatest Inventor, by Francis Trevelyan Miller, publ. John C. Winston Co. (1931), reprint publ. Kessinger Publishing (2005)
Jones, Sir Robert: dates from The Life of Sir Robert Jones, by Frederick Watson, Ayer Publishing (1980), pages 16 and 300. (According to this book, his father married in 1856, suggesting that his son Robert is more likely to have been born in 1857 than the 1855 date seen various places on the web.) (source)
Keely, John: picture from Library of Curious and Unususal Facts - Hoaxes and Deceptions, Time-Life Books, 1991, p.114
Klaus, Karl: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 110.
Knight, Margaret E.: from Library of Curious and Unusual Facts: Inventive Genius, Time-Life Books (1991), p.27.
Kornberg DNA synthesis references: "Closer to Synthetic Life," Time, 90 (22 Dec 1967): p.66; "Viable Synthetic DNA," Science News, 92 (30 Dec 1967): pp.629-630.
Kuenen, Phillip H.: picture from Milestones in Geosciences, Wolf-Christian Dullo, Springer (2003), p.2 .
L-dopa test: reported in the New York Times, 15 Jan 1970.
Leakey, L.S.B., ref. for announcement of the discovery of Australopithecus boisei skull: A new fossil skull from Olduvai, Nature 184:491-493, 1959.
Legionnaire's Disease: dates confirmed by Internet Response Team, Division of Bacterial and Mycotic Diseases, CDC.
Lapworth, Charles: picture courtesy of Lapworth Museum of Geology, University of Birmingham, England.
Leeuwenhoek, Antoine: picture from Scientists & Inventors, Feltman and Ford, Facts On File, 1986, p. 44.
Lloyd, Seton: picture from 'In Honor of Professor Emeritus Seton Howard Frederick Lloyd', Anatolian Studies (1972),. 22,  p.8.
Locke, John: electro-chronograph picture and date of $10,000 award from Sky and Ocean Joined: The U. S. Naval Observatory 1830-2000, Steven J. Dick, Cambridge Univ. Press (2002), p. 91.
Lovelace, W Randolph II: test date from Who Goes First? by Lawrence K. Altman, Random House (1987) p.28.
Lukin, Lionel: information from History of the Life-boat, and Its Work,  by Richard Lewis, Publi. Macmillan and Co. (1874), patent date: page 4; illustration: opposite page 6. See also patent date and number from A Sketch of the Origin and Progress of Steam Navigation from Authentic Documents, by Woodcroft Bennet, publ Taylor, Walton, and Maberly (1848) page 123.
Lyle, Eldon: picture from obituary in New York Times, 12 Jan 1998, page B7,  photo credit Tyler Morning Telegraph. Birth date from Social Security Death Index.
Marbut, Curtis: picture from C.F. Marbut Collection, Archive of Soil Science, Western Historical Manuscripts Collection, Columbia, Missouri; found by John Tandarich.
Marconi, Guglielmo: patent image from New and Improved, R. Baker, British Museum Publications, Ltd., p.142.
Marignac, Jean: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 237.
Mastodon and Man coexistence confirmed in Kimmswick Bone Bed: date furnished by Interpretive Resource Technician at the Mastodon State Historic Site.
Maytag wringer-washer: last date of manufacture 22 Nov 1983 confirmed by an officer of the Maytag Collectors Club who provided an image of an article describing the company's ceremony on the last day of production (apparently from a Maytag company magazine). TIME Magazine of 3 Oct 1983 refers to the end of production "by the end of the year." These show that references elsewhere on the internet to a date of 12 Oct 1983 are incorrect.
MegeMouries, Hippolyte: ref. for margerine patent date: Production de certains corps gras d'origine animale, Bulletin des lois 1875, page 210.
Meteorite, Oklahoma: reported in New York Times, 15 Jan 1970.
Meyer, Viktor: picture from A History of Chemistry, F.J. Moore rev. by William T. Hall, 3rd Ed, 1939, p. 313.
Microwave, Tappan: image from cover of replacement parts catalog (ER 63-2, 15 May 1964) for "Tappan Commerical Electronic" oven, the Tappan Company, Mansfield, Ohio.
Mill, Henry: patent description from Reference Index of Patents of Invention, from 1617 to 1852, by B. Woodcroft, publ. Patent Office, London, 1862, p.49. Date from Historical First Patents, by Travis Brown, Scarecrow Press, 1994, p.189.
Mill, Hugh: picture from Weather, June 1994, magazine of the Royal Meteorological Society.
Mower: Peter Gaillard's machine described as "not successful, however, and it is remarkable only as being the first," in The Making of America by Robert M La Follette, et al., 1906, p.95.
Müller, Sophus Otto: picture: publ. in EB courtesy of Royal Danish Embassy, London.
New York diagnostic public health lab: date from The Sanitarians: A History of American Public Health, by John Duffy.
Newton, Isaac - Seashore Quote over Pebble Background: Composite image by Webmaster, using background image of Pebbles by ? under Creative Commons Attribution-Share Alike 2.5 Generic license. (Accessed 25 Nov 2013).
Nilson, Lars: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 219.
Nutation; ref: A Letter to the Right Honourable George Earl of Macclesfield concerning an Apparent Motion Observed in Some of the Fixed Stars; By James Bradley D. D. Astronomer Royal, and F. R. S. (in Number 485) by  James Bradley, Philosophical Transactions (1683-1775), Vol. 45. (1748), pp. 1-43.
Mustard bottle illustration from Benjamin Jackson's 10 Aug 1758 advertisement, as reproduced in American Bottles and Flasks and their Ancestry, by McKearin and Wilson, p.263 (1978).
Oakley, Kenneth: Picture in Piltdown - A Scientific Forgery, by Frank Spencer, p.154, originally from an article in Picture Post, 28 Feb 1953.
Orthopaedic associations: Ref: Transactions, Vol I, Sessions 1894-95, The British Orthopaedic Society (1896), pages viii and 1. Also dates of other associations from The Evolution of Orthopaedic Surgery by Leslie Klenerman, RSM Press (2000), page 6.
Patent, Antifouling Paint: ref for Patent No. 32 issued on 31 Aug 1625 from Die Technik der Vorzeit, der geschichtlichen Zeit und der Naturvölker, by Franz Maria Feldhaus publ. Verlag von Wilhelm Engelmann (1914) p.931. (source)
Patent, Starting Block:  Patent No. 1,701,026 is the earliest patent in the 482/19 classification (exercise devices, track, starting block) found in a USPTO online *database search made 10/20/06.«
Patents: date from A History of American Manufactures from 1608 to 1860..., by J. Leander Bishop, et al., pub. E. Young (1866).
Pelletron: maximum voltage of 32.0 MV verified by National Electrostatics Corporation (email, 8 May 2006). A previously stated value of 321.5 MV is a typographical error which should instead read 32 MV (+/- 1.5 MV) where +/-1.5 MV represents a 5% uncertainty in the measurement. Also, the date was previously listed as 17 May 1979, and has been corrected to Thursday, 10 May 1979. The terminal potential of 32.0 MV has been accepted as the world's highest by the Guinness Book of World Records. The Pelletron accelerator model 25 URC remains the only electrostatic accelerator capable of running above 20 MV routinely. In the late 1970's an attempt was made by the UK government  to build a 30 MV tandem. That tandem suffered structural damage when attempting to run above 20 MV, was shut down and removed. Another attempte was made by the French government in the mid 1980's to build a 35 MV tandem accelerator. Those attempts failed with structural damage occurring in the region of 18 to 22 MV. That system has also recently been shut down.
Pepys, Samuel: Diary entry for November 16, 1666.  "This noon I met with Mr. [Robert] Hooke, and he tells me the dog which was filled with another dog's blood at the [Gresham]  College the other day, is very well, and like to be so as ever. And doubts not its [i.e,. blood transfusion] found being of great use to men."  In Latham R, Matthews W. The Diary of Samuel Pepys, vol. VII. Berkeley: University of California Press; 1974, p. 373.
Pianotyp: image from The British Library Guide to Printing: History and Techniques by Michael Twyman, University of Toronto Press (1999), page 73.
Pitot, Henri: date of paper reading (p.52) and picture (p.54) from A History of Aerodynamics by John D. Anderson, Jr., Cambridge Univ. Press (1999).
Pitot Tube: diagram from Henry P.G. Darcy and Other Pioneers in Hydraulics ASCE  Publications (2003), p.16.
Poore, Charles: photo from New York Times, 27 Jul 1971, p.36.
Priestley, Joseph: description of India Rubber quoted in Notes and Queries, Second Series, Vol. 12 (Jul-Dec 1861), publ. Bell & Daldy, London (1861), p.339. (source)
Pupin, Michael: picture from The Literary Digest, 1 Oct 1927, p.33.
Qurra, Thabit Ibn: date of death from Medieval Science, Technology, and Medicine: An Encyclopedia, by Thomas F. Glick et al., Routledge (2005),  p. 472.
Railway, Cheshunt. Ref: 3/4-mile length in Stone Blocks and Iron Rails, by Bertram Baxter, publ. David & Charles PLC (1966) page 37. Ref. (not consulted): The Times, 27 Jun 1825, p.3 which has a full description and its method of operation.
Richmann, Georg. Ref: Benjamin Franklin, A Biography by Ronald W. Clark p.87.
Richter, Hieronymus Theodor: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 198.
Say, Thomas. His birth date on 27 June 1787  is as given by Encyclopædia Britannica and Dictionary of American Biography Base Set. American Council of Learned Societies, 1928-1936.  Other sources give 27 July 1787, including at his burial site in New Harmony, Indiana (according to a feedback e-mail).
Salamander safe: photo courtesy of Gordon Wylie.
Sauveur, Albert: photo courtesy of his great granddaughter.
Savery Thomas: Date and number of ship propulsion patent: Patents for Inventions; Abridgements of Specifications Relating to Gas, and Other Motive Power Engines, A.D. 1635-1866, published by The Commissioners of Patents for Inventions (1873).
Wolfgang Schuler: Ref. Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System, Robert  Burnham Jr., Dover Publications (1978)
Sefström, Nils: picture from The Discovery of the Elements, Mary Elvira Weeks, 6th rev Ed, p. 354.
Shapley-Curtis debate: Natural History v. 104 (May 1995) p. 66+
Smoking and heart disease report information in New York Times, 8 Sep 1962, p.3.
Steel rails: date of first rolled in U.S. from Manufacturer and Builder, Dec 1884, Vol 16, No.12, pages 287-8.
In J. G. O'Hara, 'George Johnstone Stoney, F.R.S., and the Concept of the Electron', Notes and Records of the Royal Society of London , Vol. 29, No. 2 (Mar., 1975), opp. p.266.
Telegraph used for steamship Cambria's news: ref. The Nation's Newsbrokers, by Richard Allen Schwarzlose, Northwestern University Press (1989), page 88.
Telescope (name). Ref. The Discoverers by Daniel J. Boorstin, Random House (1983).
Telpher opening date and description from Electric Railways and the Electric Transmission of Power Described in Plain Terms, by Robert Luce, W.I.Harris & Co, 1886, p. 99.
Theatre, Chestnut Street: date of gaslight installation: A History of American Manufactures from 1608 to 1860 by John Leander Bishop (1866)  p.231 (source)
Thomson, Elihu: picture from Great Inventions, Abbot, Charles Greeley, Smithsonian Scientific Series, Vol 12, Plate 9, opp. p. 28
Thurber, Charles: date of death from Famous and Interesting Thurbers,
Todayinsci :Original artwork © by Colorization of underlying greyscale image © .
Toothbrush, Tek: date for advertising campaign from New York Times, 28 Mar 1939, page 30.
Travers, Morris: picture from The Discovery of the Elements, Mary Elvira Weeks, 2nd rev Ed, p. 288
Trotter, Wilfred: picture from Operations That Made History, Harold Ellis, Greenwich Medical Media (1996).
Tunnel, Mont Cenis. Reference for further reading: Opening the Mont Cenis Tunnel, Harper's Weekly, Oct. 21, 1871. Date of parliament authorization ref: Engineering in History, by Richard Shelton Kirby, publ.Dover (1990) p.484.
Vaccinations required for Boston schoolchildren: A Chronological History of the Boston Watch and Police, from 1631 to 1865, by Edward Hartwell Savage (publ. by the author, 1865), p.67.
Wallace, Wilson D. Photo in obituary by Robert F. Spencer and Elizabeth Colson in American Anthropologist (Feb 1971). 73, No. 1, p. 257. In the Wiley Online Library.
Wanamaker, John: Famous First Facts, 6th edition, states 28 arc lights and eight dynamos were installed. Lamp patent information from the Smithsonian website, which refers to 20 arc lamps being installed. The Gilded Age: Perspectives on the Origins of Modern America, by Charles William Calhoun, publ. Rowman & Littlefield (2007) pages 36-37 gives that "Initially the store had four dynamos installed and sixty-four lamps. Two years later, Wanamaker added 125 lamps, but he bought this electricity from the Brush Electric Company's plant several blocks from the store.... Wanamaker visited Edison at Menlo Park in northern New Jersey in 1883 to organize the lighting for his expansion of the store into the basement. By 1888, Wanamaker had 355 arc lamps and 80 incandescent lamps." But Calhoun (? mis-)quotes the installation date as Jan 1880. Ref. for year of radio station: The Irony of Regulatory Reform: The Deregulation of American Telecommunications, by Robert Britt Horowitz, publ. Oxford (1989) p. 112.
Wankel, Felix: picture from cover of Wankel Rotary Engine: A History, by John B. Hege, McFarland & Company (2002)
William Morton Wheeler: photo from obituary in Isis (May 1938), 28, No. 2, 421.
Wilkinson, David: picture from Slater Mill, Rhode Island, Sarah Levitt, Arcadia Publishing (1997) p.20.
Williamson, AB: picture provided by DEB Limited (
Wilson, John: ref: see Biography (1832) and Biography (1891) transcribed on this site.
Winthrop, John (1605-76): ref. for Royal Society membership in Dictionary of American Biography Base Set, American Council of Learned Societies, 1928-1936. "Leaping Hill" ref: "A Matter Too Hard for Man to Comprehend": John Winthrop Jr. and the "Leaping" Hill of Southern Maine, edited by Lauric Henneton, The New England Quarterly, vol 79, no. 3 (Sep 2006) p.461-72.]
Wrottesley, John: photo from Portraits of Men of Eminence (1864).
X-Ray, report of first clinical use in Britain. See: Jones R, Lodge O. The discovery of a bullet lost in the wrist by means of the Roentgen rays. Lancet 1896; 1(22 Feb):476-477.