The Thermometer. In Fahrenheit's Thermometer, which is universally employed in this country and Great Britain, the freezing point of water is placed at 32°, and the boiling point at 212° and the number of intervening degrees is 180. The Centigrade thermometer, which has long been used in Sweden under the name of Celsius' thermometer, and is now employed on the continent of Europe generally, marks the freezing point at Zero or 0°, and the boiling point at 100°. In Reaumur's thermometer, used in France before the revolution, the freezing point is Zero, and the boiling point 80°. Degrees below zero are distinguished by prefixing the minus sign, thus-; so that - 17° Fahr. represent a temperature of 17° lower than zero, equivalent to 49 degrees below freezing point.

86. To Convert degrees of Centigrade into degrees of Fahrenheit

86.    To Convert degrees of Centigrade into degrees of Fahrenheit. Multiply the degrees of Centigrade by 9, and divide the result by 5:- then add 32.

Thus: to find the degrees of Fahrenheit equivalent to 30 degrees of Centigrade.

30 degrees Centigrade. Multiplied by 9

Divided by 5)270

54 Add 32

Answer, 86 degrees Fahrenheit.

87. To reduce degrees of Fahrenheit to the corresponding degrees of Centigrade

87.    To reduce degrees of Fahrenheit to the corresponding degrees of Centigrade. Reverse the above process - First deduct 32 from the degrees of Fahrenheit, then multiply the difference by 5, and lastly divide the result by 9.

Thus, 86 degrees Fahrenheit. Deduct 32

Multiplied by 5

Divided by 9)270

Answer. 30 degrees Centigrade.

88. To Reduce degrees of Reaumur! to the corresponding degrees of Fahrenheit

88. To Reduce degrees of Reaumur! to the corresponding degrees of Fahrenheit. Multiply the degrees of Reaumur by 9, divide the result by 4, and then add 32.

Thus, 24° Reaumur. Multiplied by 9

Divided by 4)216

54 Add 32

Answer, 86° Fahrenheit.

89. To reduce degrees of Fahrenheit to corresponding degrees of Reaumur

89.    To reduce degrees of Fahrenheit to corresponding degrees of Reaumur.

Reverse the above process.

90. To reduce degrees of Reaumur to Centigrade

90.    To reduce degrees of Reaumur to Centigrade. Add to the degrees of Reaumur their one-fourth part.

Thus, 40° Reaumur. Add one-fourth, 10

Answer 50° Centigrade.

91. To reduce degrees of Centigrade to Reaumur

91.    To reduce degrees of Centigrade to Reaumur. Deduct one-fifth part.

Thus, 50° centigrade Deduct one-fifth 10

Answer, 40° Reaumur.

92. Table of corresponding degrees of Fahrenheit, Reaumur and the Centigrade

92. Table of corresponding degrees of Fahrenheit, Reaumur and the Centigrade.