Trails

Short routes through the collection, each one following a single thread.

Calculating before computers

Before electronic calculators, people built machines to add and multiply. This trail runs from Thomas's arithmometer through American patent models of the 1850s to 1870s, to Odhner's arithmometer and a slide rule from 1962.

Thomas ArithmometerParis, 1820Patent Model for Circular Slide Rule Invented by John W. NystromPhiladelphia, 1851Hill ArithmometerWaltham, 1857Barbour Calculating Machine ModelBoston, 1872Baldwin ArithmometerPhiladelphia, 1874Baldwin Calculating EngineSt. Louis, 1875Odhner ArithmometerSt. Petersburg, 1896Pickett N600-ES Log Log Duplex Slide RuleChicago, 1962

Finding your way

Surveyors laid out land and navigators crossed oceans with instruments like these. The trail includes a compass by David Rittenhouse, a pocket compass carried on the Lewis and Clark Expedition, and three compasses from the Gurley firm of Troy, New York.

Spy GlassLondon, about 1775Surveyor's Vernier CompassPhiladelphia, 1785Pocket compass from the Lewis and Clark Expedition, 1804-1806Lewis and Clark, 1804Bond Marine ChronometerBoston, 1812SextantNew York City, 1856Surveyor's CompassTroy, New YorkVernier Compass with TelescopeTroy, New York

Reading the sky

By measuring the height of one star and knowing the latitude, an astrolabe's user could find the time of night and the positions of other stars. These were made between about 1475 and 1780, in Europe, Persia, and the Indian subcontinent.

Italian Planispheric AstrolabeItaly, about 1475Planispheric Astrolabe Engraved with Arabic Script1504Hartman's Planispheric AstrolabeNuremberg, 1537French Planispheric AstrolabeFrance, 1548Persian Planispheric AstrolabePersia, 1611Indo-Persian Planispheric AstrolabeLahore, 1643Persian Planispheric AstrolabeIsfahan, 1715Celestial Planisphere Called Astrolabe for Latitude 41Simeon De Witt, 1780

Paris and the science of light

This trail follows four Paris makers of optical instruments: Lerebours, Soleil, Duboscq, and Koenig.

Microscope, LereboursLerebours, 1829PolariscopeLerebours, 1830PolariscopeSoleil, 1834Solar MicroscopeSoleil, 1840Projection PolariscopeDuboscq, 1880SpectroscopeDuboscqVibration MicroscopeRudolph Koenig

Finding the way in the air

Early pilots and navigators measured drift, ground speed, and time to work out their position. This trail runs from a 1918 drift plotter to the E-6B flight computer of 1942.

Plotter, DriftDrift plotter, 1918Sextant, Brandis, with Willson Bubble Telescope, EarlyBubble sextant, 1919Sight, Drift & Ground Speed, GattyGatty drift and ground speed sight, 1931Watches, Army Air Corps, Avigation [Air Navigation], A-6Navigation watches, 1934Dead Reckoning, E-6B, PrototypeE-6B prototype, 1942