HYGROGRAPHMETEOROLOGICAL APPARATUS
HYGROGRAPH
MAKER Negretti & Zambra
WHEN ca 1920 to 1940
WHAT DOES IT DO? Measures relative humidity.
HOW DOES IT WORK? Human hair changes length as it absorbs water vapour. Relative humidity is measured by this change.
Source: Meteorological Service of Canada
SNOW SAMPLER
MAKER Exco
WHEN after 1961
WHAT DOES IT DO? Measures the depth of snow and its water content.
HOW DOES IT WORK? Snow is removed with the calibrated tube and its depth is noted. The tube is then weighed to determine the water content of the snow.
Source: Meteorological Service of Canada
ANEMEVANE
MAKER James Foster, Toronto
WHEN ca 1876
WHAT DOES IT DO? This anemovane was designed by George Kingston, first director of Canada's weather service. One of the earliest remote reading instruments, it made it easier to determine wind direction. The wind turned the fans of the anemovane in the direction it was blowing. The direction was relayed through a system of shafts and gears to a dial in the observer's room below.
Source: Meteorological Service of Canada
EVENT RECORDER
MAKER Julien P. Friez
WHEN 1899 to 1913
WHAT DOES IT DO? Used with an Anemometer to measure wind speed and direction.
HOW DOES IT WORK? One needle shows the wind speed on the graph paper while the other indicates the wind direction.
Source: Meteorological Service of Canada
FORTIN BAROMETER
MAKER R. Fuess
WHEN ca 1935
WHAT DOES IT DO? Measures atmospheric pressure.
HOW DOES IT WORK? Air presses on a bulb of mercury, forcing it up a tube. Higher pressure increases the mercury level. High pressure indicates good weather.
Source: National Research Council of Canada, Instrument Division.
ASSMAN PSYCHROMETER
MAKER Casella
WHEN ca 1960
WHAT DOES IT DO? Measures humidity.
HOW DOES IT WORK? Consists of one wet thermometer and one dry one. The evaporation of the liquid on the wet one lowers its temperature. The difference of the temperature between the thermometers indicates the relative humidity.
Source: Meteorological Service of Canada
SUNSHINE RECORDER
MAKER Casella
WHEN after 1958
WHAT DOES IT DO? Measures sunshine duration.
HOW DOES IT WORK? The Sun's rays are focused by a glass sphere, burning a card. The area of card burned indicates total energy received.
Source: Meteorological Service of Canada
ACTINOGRAPH
MAKER Meteorological Service of Canada
WHEN 1950's
WHAT DOES IT DO? Measures solar and sky radiation.
HOW DOES IT WORK? This device contains two thermometers one on black metal and the other on white metal. The difference of the temperature between these thermometers indicates the solar energy level.
Source: Meteorological Service of Canada
SOLAR THERMOMETER
MAKER Taylor Instrument Co.
WHEN mid 20th century
WHAT DOES IT DO? Measures temperature.
HOW DOES IT WORK? A bulb filled with mercury is heated by the Sun's energy, causing the mercury to rise in the tube.
Source: Meteorological Service of Canada
ALIDADE
MAKER Canadian Westinghouse Co. Ltd.
WHEN 1940's to early 1950's
WHAT DOES IT DO? Measures the height of clouds.
HOW DOES IT WORK? A light beam is projected onto the base of the clouds. Its length is measured to know the altitude of the clouds.
Source: Meteorological Service of Canada
For more information on our scientific instruments, contact the Curator, Physical Sciences and Space, R.C. Brooks.
Go back to Sampler of Scientific Instruments
