Atmidometer 25 Atmospheric electricity 89 Barograph 38 Barometer precautions 40 „ description of 29 „ construction of 26 „ self-recording 36 „ warnings 43 „ syphon 30 „ wheel 33 „ corrections of 27 Beaufort’s scale of wind force 76 „ weather notation 82 Black bulb in vacuo 12 Boiling-point thermometer 36 Calorification 8 Condensation 45 Capacity, correction 27 Capillarity, correction 28 Centigrade thermometer 20 Cirro-cumulus cloud 56 Cirro-stratus cloud 56 Cirrus cloud 52 Clouds, forms of 52 „ amount of 57 Compass bearings 71 Conversion of thermometer scales 23 Cumulo-stratus cloud 56 Cumulus cloud 53 Dew-point 48 Electrification 86 Electrometers, forms of 90 Electroscope 89 Evaporation, measurement of 24 Fahrenheit’s thermometer 20 Fortin’s barometer 27 Freezing-point 20 Frost, management of hygrometer in 50 Gold-leaf electroscope 89 Glass, storm 41 Heights, measurement of 37 Hours of observation 39