Square pavement brick from Babylonia (Southern Iraq), 2nd millennium BC. Building Construction 2000-1001 BCE
The first 48-inch speculum mirror cast by Sir William Herschel in 1785 for his 'Forty-Foot' telescope at Slough, England. Original mirror for William Herschel's forty-foot telescope, 1785. Astronomy 1785
Gold pair-cased lever escapement watch by John Leroux, London 1785-6. White enamel dial signed 'Leroux London'. Central minute hand with subsidiary dials for hours and seconds. Gold hands. Details of lever escapement; all the impulse is given by the inclines on the hook-shaped teeth of the steel escape-wheel, to pointed pallets on the lever. The short lever is placed tangentially to the escape-wheel. The pallets embrace only two teeth of the escape-wheel. A jewel set in the tail of the lever moves between the adjustable banking pins. The balance staff has a cranked roller for impulse and unlocking, and a separate roller for the safety-dart. The design of this escapement provides draw. The balance is a four-arm steel wheel with timing screws and with two bi-metallic arms fixed to it, with stops to limit their outward movement. The free-sprung balance-spring is conical in shape. Full plate movement with fusee and stop lever. Movement signed 'J. Leroux Charg. Cross London'. Gold cases hallmarked for 1786 and stamped VW. Gold lever escapement watch by John Leroux. Clockmakers 1785
Copy of clay liver used for divination, original from Babylon, 2050-1750 BCE Classical & Medieval Medicine 2050-1750 BCE
1785-1873, printer; publisher; journalist; translator; inventor, Swedish Scheutz, Per Georg 1785 - 1873
