==================+=====================+=================== READING ON THE | SUGAR TO A GALLON OF WATER HYDROMETER +---------------------+------------------- Degrees | Pounds | Ounces ------------------+---------------------+------------------- 0. | | 0.0 5. | | 7.0 10. | | 14.8 15. | 1. | 7.5 20. | 1. | 14.75 25. | 2. | 12.5 30. | 3. | 9.0 35. | 4. | 7.75 40. | 5. | 8.75 45. | 6. | 13.00 50. | 8. | 5.25 55. | 10. | 4.00 60. | 12. | 8.0 ------------------+---------------------+------------------- In the second table the readings show the specific gravity of the syrup, and from that may be ascertained the proportion of sugar to a gallon of water in it. A 250 cc. cylinder, or other tall vessel deep enough to float the sacchrometer, is suitable for making the measurements. Be sure to have the eye on the level of the liquid when making the readings. If no sugar is in the water, the reading on the hydrometer will be near zero. If there is sugar in the proportion of seven ounces to a gallon of water, the reading will be at the line marked 5. SYRUPS FOR CANNING Berries --30 degrees, or 3-1/2 pounds of sugar to 1 gallon of water Sweet cherries--30 degrees Sour cherries --40 degrees Peaches --30 to 40 degrees Pears --20 to 30 degrees Plums --40 degrees [Illustration: FIG. 162. Barometer.] =304. Hygroscopes.= Hygroscopes are devices for measuring humidity. Forty-five to sixty per cent humidity is desirable in a house. This means forty-five to sixty per cent as much water as the air is capable of taking up at room temperature. Cold air is usually dryer than warmer air because cold air cannot take up as much humidity as warm air. This is analogous to the fact that warm water will dissolve more of some salts or of sugar than cold water.