1730
Hadley's Reflecting Octant
John Hadley, an English mathematician, demonstrated his new reflecting octant to the Royal Society. Using two mirrors, it could measure angles to the sun with unprecedented accuracy from the heaving deck of a ship. The sextant, as it came to be called, would be the navigator's essential instrument into the satellite age.
Tulip Era Ends in Revolt
An Albanian janissary named Patrona Halil led a mob through Istanbul that deposed Ahmed III and killed his grand vizier, Ibrahim Pasha. The new sultan, Mahmud I, burned the tulip gardens and closed the printing press. The Ottoman flirtation with Europe was over, for a while. The empire would flirt again, more cautiously.
Réaumur's Thermometer Scale
René Antoine Ferchault de Réaumur presented his alcohol thermometer to the French Academy of Sciences, using a scale where water froze at zero and boiled at eighty. Competing with Fahrenheit's mercury instrument and, later, Celsius's simpler proposal, the Réaumur scale would dominate Continental kitchens and dairies for two centuries before surrendering to Celsius.