Account of Improvements in Chronometers

15 seconds 24 hours abutments adjusting screws advantages Airy arcs of vibration Astronomer Royal attached auxiliary pieces auxiliary power balance-rim balance-spring Board of Admiralty box chronometer brass and steel centre centripetal action changes of temperature chro chrono chronometer-makers circle commonly called compensation arm compound arcs construction cylindrical piece daily rate describe diagram diameter bar diameter-bar Earnshaw Eiffe EIFFE'S INVENTION elastic error in extremes experiments extreme temperatures extremes of temperature Fahrenheit figure free ends ƒƒ heat and cold IMPROVEMENTS IN CHRONOMETERS isochronal spring lamina Letters Patent little machine little screw long vibrations Lords Commissioners mechanical middle projecting portions modification Molyneux's patent object obtain old chronometers pendulum-spring placed pocket chronometer proper public trial represented ROBERT MOLYNEUX Royal Observatory Royal Society seconds in 24 seen short vibrations shows substance supplementary compensating pieces temperature of 55 thermometer time-screws tried view of fig W. J. Frodsham