Newton's Law of Cooling: Follow up and exploration

•Isaac Newton's paper which contains Newton's Law of Cooling was investigated.•Experiments were conducted using a wind tunnel to reproduce Newton's original results.•The reason for Newton published an anonymous paper on temperature measurement was addressed. Isaac Newton's paper, in Latin, on thermal science, Scala graduum Caloris, (Scale of the Degree of Heat), published in the Philosophical Transactions (1701) is investigated in detail. This paper contains the descriptions related to Newton's Law of Cooling. We compared the Newton's temperature measurements and physical phenomena to evaluate his measurement lower than the boiling point, or 34 °N in Newton's temperature. In order to follow up the paper, we conducted Newton's experiments on forced convection using a small wind tunnel and tried to reproduce the original results, especially in the high-temperature region. We also conducted cooling experiments on natural convection. If the cooling times from the burning temperature of coal (192 °N) to the body temperature (12 °N) were 66, 80.5, and 132 min, the corresponding wind velocities were estimated to be 3.2, 2.2, and 0.7 m/s, respectively. For a wind speed of 0.7 m/s, natural convection cannot be neglected. The study also addresses the reason for why Newton published an anonymous paper on temperature measurement at temperatures higher than the boiling point of the water.