Ancient Tools and the Art of Building.--The Parthenon.-- Aqueducts of Rome.--Tombs of India.--Halls of Alhambra.-- Gothic Cathedrals.--Steam First Drew Coal, then Sawed Wood and then Stone.--Stone-cutting Machinery.--Carving.--Dressing.-- Drilling.--Tunnels.--Wonderful Work of Stone-Boring Machine on Pillars of Ohio State Capitol.--Stone Drills and Compressed Air.--Hell Gate.--Crushing Stones and Ores.--Blake’s Crusher.-- “Road Metal.”--Different Form of Crushers.--Assorting Coal.-- Steam and Coal, strong Brothers.--Compressed Air for Mining Machinery.--Mighty Picks Driven by Air.--Electric Motor.-- Machines for Screening, Loading, and Weighing.--Ore Mills.-- Separators.--Centrifugal Action.--Ore Washing.--Amalgamators: Electric, Lead, Mercury, Plate, Vacuum, Vapour, etc.--The Revolution in Mining.--Well Boring an Ancient Art.--Artesian Wells.--Coal Oil and Coal Wells.--Preceded by Discovery of Paraffine and its Uses.--Reichenbach, Young.--Petroleum Discovery.--New Industry.--Col. Drake and First Oil Well.-- Sudden Riches of Farmers.--Boring Water Wells.--Green’s Driven Wells.--The Deserts Made to Bloom as the Rose. 373 CHAPTER XXV. HOROLOGY AND INSTRUMENTS OF PRECISION. Time Measuring Instruments of Antiquity.--Sun-dial.--Clepsydra, Hour-glass, Graduated Candle.--Plato’s Bell.--The Clepsydra of Ctesibius.--Incense Sticks of Chinese.--Sun-dials of Greeks and Romans.--Candles of Alfred the Great.--Wonderful Clocks of the Middle Ages.--Henry de Vick of France, 1370.--Two Hundred Years without Advance.--Astronomers, Brache and Valherius.--1525, Zech’s Fusee.--Progenitors of Modern Watch, 1500.--1582, Swinging Lamp of Galileo.--1639, Galileo’s Book.--Huygens and the Pendulum.--Dr. Hooke’s and David Ramsey’s Inventions.--Hair-Spring Balances.--George the Third’s Small Time-Piece.--Eighteenth Century Division of Time Pieces into Hours, Minutes and Seconds.--Stem Winders.--Astronomical Discoveries and Chronometers.--Dutch, Leading Clockmakers; Germany, Switzerland.--Systems Followed in these Countries.-- Minute Sub-divisions of Labour.--Watch and Clock Making in the United States.--American System.--Wonderful Machines for every Part.--Watch factories.--Pope’s Simile.--Revolution in Nineteenth Century.--Electric System.--4000 Patents in U.S. since 1800.--Registering Devices.--“A Mechanical Conscience.”-- Cash Registers.--Voting Machines.--Electrical Recorders.-- Cyclometers.--Speed Indicators.--Weighing Scales and Machines, History of.--The Fairbanks of Vermont, 1831.--Platform and other Scales.--Spring Weighing.--Automatic Recorders of Weight and Prices.--Testing Machines, English, German, American.--The Emery Scales.--Gages, Dynamometers.--Hydraulic Testing.--Delicate Operations.--Strength of a Horse-hair and Great Steel Beam, Tested by Same Machine.--Effect on Public Works. 384 CHAPTER XXVI. MUSIC, ACOUSTICS, OPTICS, PHOTOGRAPHY, FINE ARTS.