ABSTRACT
Why was such extraordinary care taken in the use of these instruments and such uncharacteristically grim punishment meted out for their theft? First, as is well known, both clocks and sextants were crucial to accurate navigation; their loss or misuse might have seriously imperiled Cook's voyages. Secondly, they had been made in response to the British state's demand for accurate and robust instruments, and it was the duty of the state's servants (Admiralty naval officers and Board of Longitude astronomers) to use them, test them, and protect them. Finally, they were of great symbolic importance, since, by reflecting the apparent circularity of the observed heavens and the actual circularity of the spinning earth, they accurately mirrored the workings of the clockwork universe. Though timekeepers and angle measurers do not have to be circular or have components that move in circles in order to function, they invariably did so in the
courts and academies of princes and into the newly burgeoning commercial marketplace of consumers. Only the class I market (Marine, Astronomical, Surveying, Weights and Measures) existed before the scientific revolution, though with far fewer instruments than it contained by the eighteenth century. The "pre-scientificrevolution" instruments included magnetic compasses, quadrants, globes, levels, drawing instruments, gauges, and balances, while pendulum clocks, telescopes, microscopes, barometers and thermometers were added in the seventeenth century. The most important newcomers in the eighteenth century were chronometers, dividing engines, large theodolites, and achromatic lenses, all of which became commonly available only after they had first been developed in response to the demands of the British state.
