A brontometer is an apparatus used for measuring thunderstorms, invented by Richard of Paris in 1890. The brontometer consists of a drum of about 20cm wide with a coiled paper fed by a clock which causes the paper to travel at a rate of 1cm per minute and record results. Pens, which pres on the paper are connected to several meterological devices, which register the velocity of the wind, rainfall and atmospheric presure. Other pens worked by keys enable the observer to record the precise time of thunder and lightning.
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