Degrees Equal Parts of Heat. of Heat. 0 0 Freezing point of water. 1 12 Blood-heat. 2 24 Heat of melting wax. 3 48 Melting point of equal parts of tin and bismuth. 4 96 Melting point of lead. 5 192 Heat of a small coal-fire. The first column of this table contains the degrees of heat in arithmetical progression, and the second in geometrical progression,—the second degree being twice as great as the first, and so on. It is obvious from this table, that the heat at which equal parts of tin and bismuth melt is _four_ times greater than that of blood-heat, the heat of melting lead _eight_ times greater, and the heat of a small coal-fire _sixteen_ times greater. This table was constructed by the help of a thermometer, and of red-hot iron. By the former he measured all heats as far as that of melting tin; and by the latter he measured all the higher heats. For the heat which heated iron loses in a given time is as the total heat of the iron; and therefore, if the times of cooling are taken equal, the heats will be in a geometrical progression, and may therefore be easily found by a table of logarithms. He found by a thermometer constructed with linseed oil, that if the oil, when the thermometer was placed in melting snow, occupied a space of 1000 parts, the same oil, rarefied with _one_ degree of heat, or that of the human body, occupied a space of 10256; in the heat of water beginning to boil, a space of 10705; in the heat of water boiling violently, 10725; in the heat of melted tin beginning to cool, and putting on the consistency of an amalgam, 11516, and when the tin had become solid, 11496. Hence the oil was rarefied in the ratio of 40 to 39 by the heat of the human body; of 15 to 14 by the heat of boiling water; of 15 to 13 in the heat of melting tin beginning to solidify; and of 23 to 20 in the same tin when solid. The rarefaction of air was, with the same heat, _ten_ times greater than that of oil, and the rarefaction of oil _fifteen_ times greater than that of spirit of wine. By making the heats of oil proportional to its rarefaction, and by calling the heat of the human body 12 parts, we obtain the heat of water beginning to boil, 33; of water boiling violently, 34; of melted tin beginning to solidify, 72; and of the same become solid, 70.