A direct-vision nephoscope which is constructed in the following manner: a comb consisting of a crosspiece containing equispaced vertical rods is attached to one end of a column eight to ten feet long and is supported on a mounting that is free to rotate ...

See Koschmieder's law.

See aneroid capsule.

A hygrometer using goldbeater's skin as the sensitive element. Variations of the physical dimensions of the skin caused by its hygroscopic character indicate relative humidity. (Note: Goldbeater's skin is the prepared outside membrane of the large intesti ...

The unit of speed in the nautical system; one nautical mile per hour. It is equal to 1.1508 statute miles per hour or 0.5144 meters per second.

Winds from the four cardinal points of the compass; that is, north, east, south, and west winds.

Wind with a speed between 4 and 27 knots (4 and 31 mph); Beaufort scale numbers 2 through 6.

A psychrometer in which the ventilation is provided by a suction fan.

An instrument that automatically records pressure and temperature.

The height at which the maximum wind speed occurs, determined in a winds-aloft observation.

Apparatus using the combined simultaneous action of a bimetallic thermometer and a hair hygrometer to move a needle in front of a divided scale. fts construction permits dew point variations to be indicated approximately.

A thermometer whose sensitive element has been made to resemble a black body by covering it with lamp black. The thermometer is placed in an evacuated transparent chamber which is maintained at a constant temperature. The instrument responds to insolation ...

An up slope wind due to local surface heating. Opposite of katabatic wind.

General name for an instrument which measures the evaporation rate of water into the atmosphere. See clay atmometer, evaporation pan, evapotranspirometer, Livingston sphere, Piche evaporimeter, radio atmometer.

pattern barometer-Mercurial barometer with a fixed scale and cistern and which therefore requires only one adjustment before each reading.

The frequency of a carrier wave.

The amount of precipitation captured by a rain gauge.

A measure of the relative power, or of the relative values of two flux densities, especially of sound intensities and radar power densities. The decibel is derived from the less frequently used unit, the bel, named in honor of Alexander Graham Bell.

An instrument which measures evaporation by measuring the loss of water from a burette reservoir through a ceramic disc.

An ion counter of the aspiration condenser type, used for the measurement of the concentration and mobility of small ions in the atmosphere.