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
Beckmann thermometer inverted and gently tapped so that the mercury in the reservoir lodges in the bend (B) at the end of the stem. Next, the bulb is heated until the mercury in the stem joins the mercury in the reservoir. The thermometer is then placed in a bath one or two degrees above the upper limit of temperatures to be measured. The upper end of the tube is gently tapped with the finger, and the mercury suspended in the upper part of the reservoir will be jarred down, thus separating it from the thread at the bend (B). The thermometer will