Daniel Gabriel Fahrenheit research suggests that the Fahrenheit family originated in Hildesheim. Daniel's grandfather moved from Kneiphof in Königsberg (present-day Kaliningrad) to Danzig and settled there as a merchant in 1650. His son, Daniel Fahrenheit (the father of the subject of this article), married Concordia Schumann, daughter of a well-known Danzig business family. Daniel was the eldest of the five Fahrenheit children (two sons, three daughters) who survived childhood. His sister, Virginia Elizabeth Fahrenheit, married Benjamin Ephraim Krueger of an aristocratic family from Danzig. Daniel Gabriel began training as a merchant in Amsterdam after his parents died on 14 August 1701 from eating
Beckmann thermometer (R on diagram) at the upper end of the tube, by means of which the quantity of mercury in the bulb can be increased or diminished so that the instrument can be set to measure temperature differences at either high or low temperature values. In contrast, the range of a typical mercury-in-glass thermometer is fixed, being set by the calibration marks etched on the glass or the marks on the printed scale. In setting the thermometer, a sufficient amount of mercury must be left in the bulb and stem to give readings between the required temperatures. First, the thermometer is