RULES FOR CONVERTING ONE
SCALE INTO THE OTHER.
To convert Fahrenheit degrees into those of Centigrade: Subtract 32, multiply by 5, and divide by 9. For example:
104° F. - 32° = 72; 72 × ⁵/₉ = 40° C.
To reduce Centigrade degrees into those of Fahrenheit: Multiply by 9, divide by 5, and add 32. For instance:
40° C. × ⁹/₅ = 72 + 32 = 104° F.
TABLE OF THERMOMETRIC EQUIVALENTS.
| 36° | Centigrade | 96.8° | Fahrenheit. |
| 37° | “ | 98.6° | “ |
| 38° | “ | 100.2° | “ |
| 39° | “ | 102.2° | “ |
| 40° | “ | 104.0° | “ |
| 41° | “ | 105.8° | “ |
| 42° | “ | 107.6° | “ |
TO CONVERT THERMOMETER READINGS.
A correspondent of the “Lancet” (London) offers a new alternative method of converting degrees Centigrade into degrees Fahrenheit, which may be found easier to perform mentally than the usual method, because the factors can be more easily retained in the memory. This method consists of multiplying the centigrade figures by 2, deducting one-tenth of the product, and adding 32.
Example (a), 30° C.= 86° F.
Method: 30 × 2 = 60. 60 - 6 = 54. 54 + 32 = 86.