Commenting on the experiments of Sir Isaac Newton with the iron pyrometer, Amontons devised similar ones. Assuming that the temperature increased in arithmetical progression throughout a rod of iron 59 inches long, he obtained the following results.
Temperatures Obtained With Amonton's Pyrometer.
| Thin glass melted at | 4 | pouces 4 lignes. |
| Lead melted at | 8 | pouces 6 lignes. |
| Gunpowder ignited at | 8 | pouces 6 lignes. |
| Tin melted at | 11 | pouces |
| Alloy of 3 tin and 2 lead melted at | 12 | pouces |
| Water boiled at | 22 | pouces |
| White wax melted at | 30 | pouces 8 lignes. |
| Tallow melted at | 39 | pouces |
| Butter melted at | 42 | pouces |
In his paper published in the "Mémoirs de Paris" (1703, p. 50) Amontons makes the oracular statement "heat is the soul of nature, and it is very important for physicists to be able to measure it accurately."
Fourteen years later, Jakob Hermann, a mathematical physicist of Basle, seeking to make thermometrical readings independent of corrections for barometric pressure, proposed to close the tubes of Amontons' air thermometers by fusing the upper ends; this form of
