Education | Educational Material | Entomology -- Europe. | Entomology -- United States. | Exploration. | Family Correspondence | General Correspondence | Hayes, Rutherford B., 1822-1893 | Hospitals -- United States -- Civil War, 1861-1865. | Insects. | LeConte family. | LeConte, John L. (John Lawrence), 1825-1883 | Mason, Otis Tufton, 1838-1908 | Medicine | Medicine -- United States -- History -- 19th century. | Melsheimer, Frederick Valentine, 1749-1814 | Miscellaneous | Natural history -- United States. | Notebooks | Osten-Sachen, Carl Robert, -- freih | Science and technology | Scientific Data | Sketchbooks | Ulke, Henry, 1821-1910 | United States. -- Army. | United States. -- Army. -- Corps of Topographical Engineers.

Aerial Phenomena Research Organization, Inc. | Aeronautics and Astronautics | Air and Space Magazine | Airships | Alien abduction | Allen, Woody, 1935- | American Institute of Aeronautics and Astronautics | American Physical Society | Apollo 12 (Spacecraft) | Apollo 8 (Spacecraft) | Association pour l'Investigation Historique des Phenomenes Insolites | Audiotapes | Ballistic missiles | Balloons. | Bartholomew, Robert E., 1958- | Canada. Canadian Army | Center for UFO Studies | Close Encounters of the Third Kind | Combustion, Spontaneous human | Committee for the Scientific Investigation of Claims of the Paranormal | Condon Report | Condon, Edward Uhler, 1902-1974 | Cronkite, Walter, 1916 - | Crop circles | Denver UFO Society | Department of Scientific and Industrial Research | Directed energy weapons | Discovering science | Eastern Airlines | Esterle, Alain | Fate magazine | Focus magazine | Friend, Robert J. | Fry, Daniel W. | Fund for UFO Research, Inc. | GEPAN (Unidentified Aerospace Phenomena Study Group)-French Space Agency | Gemini Project (U.S.) | Gill, William B. | Goldwater, Barry | Graham, Lee M. | Haines, Richard F. | Harder, James A. | Helicopters | Hill Abduction Case, 1961 | Hopkins, Bud | Howe, Linda | Hynek, J. Allen (Joseph Allen), 1910-1986 | Hypnosis | Jacobs, David M. (Michael), 19 | Johnson, Lyndon B. (Lyndon Bai | Journal of Abnormal Psychology | Journal of Scientific Exploration | Jung, C. G. (Carl Gustav), 187 | Klass, Philip J. | Klass, Philip J. | Kral, Elmer | Life magazine | Littmann, Mark | MARINER 4 (Spacecraft) | MUFON | Maccabee, Bruce S. | Mack, John E., 1929- | McDonald, James E., 1920 - | Mead, Margaret, 1901-1978 | Menzel, Donald Howard, 1901-1976 | Miscellaneous | Mysteries old and new | National Aeronautics and Space Administration (NASA) | National Enquirer | National Investigations Committee on Aerial Phenomena. | National Research Council Canada | New York Review of Books | New York Times | New Yorker | Newspaper clippings | North Atlantic Treaty Organization | Oberg, James E., 1944 - | Optical illusions | Parade Magazine | Patuxent Naval Air Test Center (Md.) | Photographic analysis | Photographs | Photomethods | Playboy | Project Apollo (U.S.) | Project Blue Book (U.S.) | Psychiatry | RADAR | RB-47 UFO Case, July 1957 | Read | Royal Canadian Mounted Police | Sagan, Carl, 1934-1996 | Salisbury, Frank B. | Satellites | Saucer smear | Scholastic Book Services | Schroth, David A. | Second Look | Sheaffer, Robert | Skeptical Inquirer | Smithsonian Institution | Society for the Investigation of the Unexplained | Soviet Union | Space based weapons | Sprinkle, R. Leo, 1930 - | Stacy, Dennis | Steiger, Brad | Strategic Defense Initiative | Strategy for Peace Conference | Strieber, Whitley | Taves, Ernest H. (Ernest Henry | Unidentified flying objects | Unidentified flying objects -- Religious aspects | Unidentified flying objects -- Sightings and encounters | Unidentified flying objects in motion pictures | Unidentified flying objects in popular culture | United Airlines | United Nations. Atomic Energy Commission | United States Air Force | United States Air Force--Operation Blue Book | United States. Army | United States. Central Intelligence Agency | United States. Coast Guard | United States. Congress | United States. Federal Bureau of Investigation | United States. House of Representatives | United States. Navy | United States. Office of Naval Intelligence | University of Colorado-UFO Study | University of Michigan | Vallee, Jacques | Venus (Planet) | Videotapes | Washington Post | World Almanac Book of the Strange | Zond IV (Spacecraft)

Abenaki language | Abolition, emancipation, freedom | Abolitionists. | Acquisitions (Libraries) | Actors | Aeronautics -- History | Agassiz, Louis, 1807-1873 | Agricultural exhibitions | Agriculture -- Missouri | Air -- Purification -- Equipment and supplies | Albert Medal | Alcoholic beverage industry -- United States | Alphabets | America -- Antiquities. | American Anti-Vivisection Society | American Philosophical Society | American Philosophical Society -- Prizes | American Philosophical Society. Library | American loyalists. | Anatomy -- Study and teaching. | Animal magnetism. | Antarctica -- Discovery and exploration. | Anthropology | Antiquities -- Collection and preservation | Aquariums. | Archaeology -- Mexico | Archaeology -- United States. | Architectural drawings. | Architecture | Archives | Arithmetic. | Art -- Exhibitions | Astronomical instruments. | Astronomy | Astronomy -- Early works to 1800 | Atlases | Balloons. | Bank notes -- Forgeries | Bank notes -- Great Britain | Banks and banking -- Pennsylvania | Barometers. | Bartram's Garden (Philadelphia, Pa.) | Beaver Meadow Railroad and Coal Company | Bible - Criticism, interpretation, etc. | Bible. New Testament | Bible. O.T. Psalms, II, 1 -- Sermons | Biology. | Birds | Birds -- North America | Birds -- Pictorial works | Birmingham (Pa.) | Bonds (financial instruments). | Bookbinding | Bookplates | Books -- Auction catalogs | Booksellers and bookselling | Boston Port Bill, 1774 | Boston Tea Party, Boston, Mass., 1773 | Botany | Botany -- Catalogs -- France | Botany -- Catalogs -- Great Britain | Botany -- Catalogs -- United States | Botany -- New York (State) | Braddock's Campaign, 1755. | Brandywine, Battle of, 1777 | Bridges. | Broadsides. | Building materials | Bunker Hill, Battle of, 1775 | Business Records and Accounts | Business cards | Cables -- Atlantic Ocean | Calculators. | Calendars | Campus Martius (Marietta, Ohio) | Canada -- Description and travel | Canada -- Maps | Canals -- Pennsylvania | Capture at sea | Carriages and carts | Cements, Adhesive | Cetacea | Charities -- England -- London | Chemicals | Chemistry | Chemistry -- History | Chemistry -- Nomenclature | Chemistry -- Study and teaching | Cherokee language -- Alphabet | Cherokee language -- Texts | Chesapeake and Delaware Canal | Chile | China | China -- Medical care | Chinese language | Chipewyan language | Christian calendars | Christianity | Christmas | Chronometers | Church buildings -- Pennsylvania-Philadelphia | Church of Scotland | Civilization -- Early works to 1800 | Clocks and watches. | Coinage. | Coins | Colombia -- Census | Columbia (Symbolic character) | Columbus, Christopher, 1451-1506 | Comets -- Orbits | Congratulations, greetings, thanks | Conjoined twins | Connecticut | Conservation of natural resources. | Constitutional history -- United States | Cotton | Cotton -- Diseases and pests | Cotton -- Statistics | Counting | Court summons | Courtship -- Songs and music | Criticism -- History | Crucero Iberia | Crusades | Cuba -- Statistics, Vital | Cutlery | Cyclopedia | Dance cards | Darwinism. | Daylight saving | Delaware Indians | Delaware Indians -- Religion | Democratic National Convention (1864 : Chicago, Ill.) | Design | Dickinson College -- History -- Sources | Dwellings -- Heating and ventilation | Earth (Planet) | Eclipses. | Ecton (Northamptonshire, England) | Education | Education -- Congresses | Education -- South Carolina | Education -- Study and teaching -- England. | Education -- United States. | Egypt -- Civilization. | Eidouranion | Electricity | Electrotherapeutics | Encyclopedias and dictionaries, French | English language | Entomology -- United States. | Episcopal Church -- Pennsylvania -- Philadelphia | Eskimo languages | Essays. | Fairmount Water Works (Philadelphia, Pa.) | Fire extinction -- Pennsylvania -- Philadelphia | Fisheries -- Great Britain | Fishes -- Catalogs and collections | Fishes -- Italy | Flags -- United States. | Flight | Flour | Forests and forestry -- United States -- Maps | Forests and forestry -- United States. | Foundries | France -- History. | France. Chambre des pairs | France. Code civil | Franklin (Aircraft carrier) | Franklin Institute (Philadelphia, Pa.) -- History | Franklin Journal | Franklin, Benjamin, 1706-1790 | Franklin, Benjamin, 1706-1790 | Franklin, Benjamin, 1706-1790 -- Imprints | Freemasonry -- France -- History. | Freemasons | Freemasons -- Pennsylvania | French language | Friendly Association for Regaining and Preserving Peace with the Indians by Pacific Measures | Fruits | Furnaces | Gas-lighting. | Genetics -- History. | Genetics -- Societies, etc. | Geodesy | Geography -- Europe | Geologists. | Geology | Geology -- Great Britain. | Geology -- Pennsylvania. | Geology -- Tables | Geology, Stratigraphic. | Girard College | Girls' Schools -- France -- Paris | Goldsmith, Oliver | Gorlitz (Dresden, Germany). Gymnasium | Grapes | Great Britain -- Colonies | Great Britain -- Colonies -- America | Great Britain -- Commerce -- West Indies. | Great Britain. Treaties, etc. United States, 1783 Sept. 3 | Great Central Fair for the U.S. Sanitary Commission (1864 : Philadelphia, Pa.) | Grinnell Expedition, 2d, 1853-1855 | Gulf Stream | Haiti | Haiti -- History -- Sources | Harvard University -- Students | Hessians | Historic buildings -- Canada | Historic buildings -- United States | History of the earth and animated nature | History. | Hollywood (Md.) | Honors -- Royal Society (Great Britain) | Hospitals -- Pennsylvania -- Philadelphia. | Hospitals -- United States -- Civil War, 1861-1865. | Human beings -- Origin | Hybridization | Hymns | Hypnotism | Independence Hall (Philadelphia, Pa.) | Independence National Historical Park (Philadelphia, Pa.) | Indians of North America | Indians of North America -- Antiquities | Indians of North America -- Government relations | Indians of North America -- History | Indians of North America -- Languages | Indulgences | Inland navigation -- United States | Insurance -- Great Britain | Invitations. | Iron and steel bridges | Iroquois Indians -- Agriculture | Jena, Battle of, Jena, Germany, 1806 | Jesus Christ | Jupiter (Planet) | Kings and rulers | Laboratories | Labrador (N.L.) | Lamps | Land use -- Ohio | Landscape architecture | Language and languages -- Orthography and spelling | Latin language | Law -- Periodicals | Law -- Virginia | Lectures, public speaking | Lectures. | Lehigh Coal and Navigation Company | Liberty Bell | Library rules and regulations | Library science -- Congresses | Life preservers | Light | Lightning | Lightning conductors | Lions | Lippincott's magazine of literature, science and education | Locks and keys | Locusts | London (England) -- Buildings. | London (England) -- Maps | Longitude. | Lord's prayer | Lotteries | Lowell Observatory | Lumadrama | Lyceums. | Machinery. | Magic squares | Magna Carta | Mammoths. | Maps | Maps. | Martial law -- Philadelphia (Pa.) | Massachusetts -- Finance | Mastodon | Mastodon -- Exhibitions | Mathematical instruments | Mauritius | Maxims | Medical sciences -- Periodicals | Medicine -- Congresses | Medicine -- Humor | Medicine -- Study and teaching. | Membership cards | Menageries -- Boston (Mass.) | Menageries -- Great Britain | Menageries -- Philadelphia | Menus. | Mercantile Library of Philadelphia | Merino sheep | Mesmerism. | Meteorology | Meteorology - Observations | Meteorology -- Observations -- England -- London | Meteorology -- Observations. | Meteorology -- Tables | Meteors. | Mexico -- History -- 1821-1861 | Mexico -- History -- Sources | Microscopy. | Mineralogy | Missionaries -- China. | Mississippi River Valley -- Description and travel | Missourium | Mohawk Indians | Mohawk language -- Texts | Mohegan Indians -- Religion | Mollusks. | Money | Moral philosophy | Moravians -- Missions | Morphology. | Mosquitoes. | Mothers | Mound-builders -- United States | Mounds -- United States | Mount Vernon School (Boston, Mass.) | Museums | Museums -- New York (State) -- New York. | Museums -- Pennsylvania -- Philadelphia -- 19th century. | Music -- Scores. | Musical scores. | Mustard | Mysticism | National Academy of Sciences | National songs -- United States | Natural Philosophy | Natural history | Natural history -- Periodicals | Natural history -- Societies, etc. | Natural history -- South America | Natural history -- Technique | Natural history -- United States. | Naturalists. | Nebulae | New Orleans Canal and Banking Company | Newspapers -- Pennsylvania -- Philadelphia | Occultism | Odometers | Official Government Documents and Records | Olivier, Charles P. (Charles Pollard), 1884-1975 | Oneida Community | Optical instruments | Orators | Ordnance | Oregon | Ozone | Painting -- Exhibitions | Paleontology | Paleontology -- Missouri | Paper money -- United States -- History -- Revolution, 1775-1783 | Paris (France) -- Description and travel. | Paris (France) -- History -- 1715-1789. | Passports. | Patent medicines | Patriotische Martyrer | Peale's Museum (Philadelphia, Pa.) | Pennsylvania -- Description and travel. | Pennsylvania -- History | Pennsylvania -- History -- Colonial period, ca. 1600-1775 | Pennsylvania -- History -- Revolution, 1775-1783 | Pennsylvania -- Politics and government -- To 1775. | Perpetual calendars | Perpetual motion | Pharmacology. | Philadelphia (Pa.) -- Finance | Philadelphia (Pa.) -- History -- Revolution, 1775-1783. | Philadelphia (Pa.) -- History. | Philadelphia (Pa.) -- Social life and customs -- 19th century. | Philadelphia (Pa.) -- Statistics, Vital | Philadelphia (Pa.)-History -- Revolution, 1775-1783. | Philadelphia (Pa.). Militia | Phrenology. | Physical geography -- Canada | Physical instruments | Physicians | Physicians. | Phytogeography -- United States -- Maps | Planets | Planets -- Observations | Plants -- Collection and preservation. | Plows. | Poetry | Polarization (Light) | Political geography | Political satire | Poor laws -- Great Britain | Portraits. | Portsmouth (N.H.) -- Statistics, Vital | Postal service -- History | Postal service -- United States. | Presidents -- United States -- Autographs | Presidents -- United States -- Election -- 1804 | Presidents -- United States -- Election -- 1840 | Presidents -- United States -- Election -- 1864 | Presidents -- United States. | Prices | Prices -- France | Prices -- Italy -- Trieste | Prices -- Pennsylvania -- Philadelphia | Prices -- United States | Princeton, Battle of, Princeton, N.J., 1777 | Printed Material | Printing machinery and supplies | Printing presses | Prisons | Privateering | Prizes | Processions -- Pennsylvania -- Philadelphia | Promissory notes | Propaganda, American | Prophecies | Quakers. | Railroads -- Mexico | Railroads -- Pennsylvania | Railroads -- Pennsylvania -- History | Railroads. | Real property -- Pennsylvania. | Real property. | Redwood family | Reigate and Godstone Railway | Religious education -- Massachusetts | Retired women -- France -- Paris | Rewards programs (Criminal investigation) | Roads -- Pennsylvania | Roots, Numerical | Royal College of Physicians of London | Royal Humane Society (London, England) | Rutgers College | Saint Croix (United States Virgin Islands) | Salt industry and trade | Scales (Weighing instruments) | Schools -- Denmark | Science | Science -- Congresses | Science -- History -- Study and teaching | Science -- Philosophy -- Study and teaching | Science -- Societies, etc. | Science -- Study and teaching. | Scientific apparatus and instruments. | Scientific expeditions. | Scientists. | Seals and labels (Philately) -- Pennsylvania -- Philadelphia | Seeds -- Catalogs | Seneca | Serpents | Sheffield (England) | Shipbuilding | Shippen, William, 1736?-1808 | Shippensburg (Pa.) | Ships, Iron and steel -- Great Britain | Shorthand. | Signals and signaling | Silk | Slavery -- Pennsylvania. | Slavery -- United States. | Slaves, slavery, slave trade | Slavey language | Smallpox | Smallpox -- Vaccination | Social cards | Societies. | Society of Friends | Society of Friends -- Great Britain. | Solar eclipses. | Song sheets | South America -- Discovery and exploration -- 19th century. | South Carolina -- Politics and government | Southern States -- Description and travel. | Southwark (Philadelphia, Pa.) | Spelling reform | Stamp Act, 1765 | Stars. | Steam | Steam-carriages | Steam-engines. | Steam-navigation | Steamboats -- United States. | Stoves | Strikes and lockouts | Success | Sugar beet | Sun | Susquehanna County (Pa.) | Sweden. Treaties, etc. United States, 1783 April 3 | Tariffs | Taxation -- Massachusetts | Taxation -- United States | Te Deum laudamus (Music) | Telegraph | Telescopes | Temper | Temperature -- Newfoundland -- St. John's | Temperature measurements. | Texas -- History -- Republic, 1836-1846 | Texas. Navy | Theology | Thermometers | Tickets. | Tobacco -- Commerce | Tobacco industry -- Bermuda Islands | Tobacco industry -- Virginia | Tornadoes | Trains -- Central Europe | Transactions of the American Philosophical Society | Transylvania University | Travel | Treaties. | Trees -- North America. | Trees. | Trieste (Italy) -- Commerce | Trust indentures. | Tunnels -- England -- Thames River | Type and type-founding -- Specimens | Typhus fever. | U.S. Coast and Geodetic Survey | United Nations | United States - Politics and government | United States - Politics and government - 1783-1809 | United States -- Anniversaries, etc. | United States -- Centennial celebrations, etc. | United States -- Foreign relations -- China | United States -- History -- Civil War, 1861-1865 -- Songs and music | United States -- History -- French and Indian War, 1755-1763 | United States -- History -- Revolution, 1775-1783 | United States -- History -- Revolution, 1775-1783 -- American forces | United States -- History -- Revolution, 1775-1783 -- Causes | United States -- History -- Revolution, 1775-1783 -- Participation, German | United States -- History -- Revolution, 1775-1783 -- Personal histories. | United States -- History -- Revolution, 1775-1783 -- Personal narratives | United States -- History -- Revolution, 1775-1783 -- Prisoners and prisons | United States -- History -- Revolution, 1775-1783 -- Sources | United States -- Military policy | United States -- Statistics | United States History Civil War, 1861-1865 Caricatures and cartoons | United States. Army | United States. Congress (2nd, 1st session : 1791-1792) | United States. Constitution | United States. Continental Army -- Organization | United States. Continental Army -- Staff -- Biography | United States. Declaration of Independence | United States. Navy -- Warrant officers | Uruguay -- History | Various authors | Vietnamese conflict, 1961-1975 | Virginia. Declaration of Rights | Vivisection | Vivisection -- 19th century | Volapük | Warships | Washington Hall | Water -- Purification | Water -- Purification -- Filtration | Water mills | Wayne, Anthony, 1745-1796 | Weights and measures. | Whales | Wharton School | Wills. | Wine and wine making | Women -- Education | Women -- Employment | Wood -- Preservation | Yale University | Zoology | Zoology -- India | Zoology -- Italy | Zoology -- Pictorial works | Zoology -- Study and teaching.