Irish Famine (1740–41) affect economies, energy sources, and politics. Although no barometric or temperature readings for Ireland survive from the Great Frost, a scattered few records survive from Englishmen who made personal readings. The mercury thermometer was invented 25 years earlier by the German pioneer Daniel Gabriel Fahrenheit. Indoor values during January 1740 were as low as . The one outdoor reading that has survived was stated as "thirty-two degrees of frost." This did not include the effects of the wind chill factor, which would have been severe. This kind of weather was "quite outside the Irish experience," notes David Dickson, author of
Six's thermometer Six's thermometer Six's thermometer is a registering thermometer which can record the maximum and minimum temperatures reached over a period of time, for example 24 hours. It is used to record the extremes of temperature at a location, for instance in meteorology and horticulture. It was invented by a British scientist James Six, born in Canterbury, in 1780; the same basic design remains in use. It is also commonly known as a maximum–minimum, minimum–maximum, maxima–minima or minima–maxima thermometer, of which it is the earliest practical design. The thermometer indicates the current temperature, and the highest and lowest temperatures since last