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Thompson's Astatic Galvanometer

MAKER Elliott Bros.

WHEN late 19th century

WHAT DOES IT DO? Detects small electric currents.

HOW DOES IT WORK? Electricity passing through a wire coil creates a magnetic field which twists a suspended magnet and mirror. A light beam reflects off the mirror and onto a scale.

Source: National Research Council of Canada, Electrical Engineering (originally used by Energy, Mines and Resources)

Reaction Apparatus

MAKER Dr. Ken Cashion and Dr. John Polanyi

WHEN 1960

WHAT DOES IT DO? In 1986, John Polanyi won the Nobel prize in chemistry. Some 25 years earlier, he and Dr. Cashion had built special instruments to study the dynamics of chemical reactions. As atoms collide inside the glass cell they give off light detected by a spectrometer. This light changes as a reaction continues. Analyzing the light patterns lets us see exactly how atoms combine. Polanyi's research was done at Ottawa's National Research Council and the University of Toronto. It eventually led to the development of the chemical laser.

Source: Dr. John Polanyi, University of Toronto


MAKER Ph. and F. Pellin

WHEN ca 1880

WHAT DOES IT DO? Measures the concentration of sugar.

HOW DOES IT WORK? Light is passed through a solution. The concentration of sugar is determined by the degree light is rotated when passing through the sample.

Source: Montreal University, Department of Physics

Optical Microscope and Electron Microscope

Optical Microscope
Optical Microscope: Topley Co.
Electron Microscope: RCA

Optical Microscope: ca 1890-1900
Electron Microscope: ca 1965

Desktop Electron Microscope

Desktop Electron Microscope

WHAT DOES IT DO? Invented in 1591, the optical microscope uses light and lenses to magnify objects. By 1870 scientists realized that the nature of light would limit magnification to only 2000 times. In 1932, the first electron microscope was invented. It replaced light with streams of electrons and used magnets instead of lenses. Albert Prebus and James Hillier built Canada's first electron microscope at the University of Toronto in 1939. Today, electron microscopes can magnify an object by over 500 million times.

Current Balance

MAKER Kelvin, Bottemley and Baird

WHEN ca 1907

WHAT DOES IT DO? The current balance, invented by Lord Kelvin in 1882, was the first instrument to measure electric currents precisely. Instead of having pans, this balance has wire coils. Four are fixed, two are movable. Currents passing through all the coils creates a magnetic field which repels the movable coils. They are rebalanced by moving the sliding weight and adding precise masses. The electric balances we find in grocery stores today use a similar principle.

Source: National Research Council of Canada

Drysdale's Potentiometer

MAKER H. Tinsley and Co.

WHEN 1898 to 1905

WHAT DOES IT DO? Measures AC or DC voltages and currents.

HOW DOES IT WORK? A test circuit is connected to an internal battery. Resistances are selected until a moving galvanometer indicates a balance.

Source: Department of Consumer and Corporate Affairs

Radiation Monitor

MAKER Nuclear Instruments Ltd., Winnipeg

WHEN ca 1965

WHAT DOES IT DO? Measures Beta and Gamma particle emissions from radioactive materials.

HOW DOES IT WORK? It contains a tube filled with gas under high voltage. Radioactive particles short-circuit the gas creating a pulse of electricity.

Source: National Research Council of Canada, Physics

Hydrometer Set

MAKER August Eichhorn

WHEN late 19th century

WHAT DOES IT DO? Measures specific gravity.

HOW DOES IT WORK? The hydrometer floats in the liquid. The level where the surface of the liquid touches the scale indicates the specific gravity.

Joly Hydrostatic Balance

MAKER Fisher Scientific

WHEN ca 1960

WHAT DOES IT DO? Precisely measures the density of an object.

HOW DOES IT WORK? Small objects are placed on the pan which is suspended in water. The volume of water displaced is used to calculate density.

Source: Gloucester High School

Blowpipe Set

MAKER J.T. Letcher

WHEN ca 1875

WHAT DOES IT DO? Used for chemical analysis.

HOW DOES IT WORK? Samples are heated over the blowpipe until they break down. They are then studied by adding various chemicals.

Source: National Research Council of Canada, Archives

Laboratory Balance

MAKER Sartorius-Werke

WHEN 1932

WHAT DOES IT DO? Used for precision weighing of chemicals.

HOW DOES IT WORK? The chemical is placed on one pan. Weights are added to the other pan until the two pans balance.

Source: National Research Council of Canada, Biological Sciences

For more information on our scientific instruments, contact the Curator, Physical Sciences and Medicine, David Pantalony.

Go back to Sampler of Scientific Instruments