"The Fahrenheit hydrometer of constant volume is made of glass, the bulb at the bottom being loaded with mercury or shot." — Avery, 1895

Hydrometer

"The Fahrenheit hydrometer of constant volume is made of glass, the bulb at the bottom being loaded…

A Centigrade and Fahrenheit thermometer side by side

Thermometer

A Centigrade and Fahrenheit thermometer side by side

"A bulb of liquid is placed in the base of the glass graduated tube. As temperature increases, the volume of the liquid increases and it expands up the tube where its level is read on the graduated scale." —Quackenbos 1859

Thermometer

"A bulb of liquid is placed in the base of the glass graduated tube. As temperature increases, the volume…

A thermometer showing both Fahrenheit and Centigrade scales.

Thermometer

A thermometer showing both Fahrenheit and Centigrade scales.

"Used to compare the temperature between two environments. As the temperature in one bulb increases, the liquid reading changes according to the air expanding within the bulb. If both bulbs are the same temperature, the scale measures zero." —Quackenbos 1859

Differential Thermometer

"Used to compare the temperature between two environments. As the temperature in one bulb increases,…

"Thermometers showing the corresponding points for water's freezing and boiling." -Avery 1895

Fahrenheit and Celcius scale Thermometers

"Thermometers showing the corresponding points for water's freezing and boiling." -Avery 1895

Dual Lab Thermometers 0 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 0 Degrees Fahrenheit

Dual Lab Thermometers 5 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 5 Degrees Fahrenheit

Dual Lab Thermometers 10 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 10 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 15 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 20 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 25 Degrees Fahrenheit

Dual Lab Thermometers 30 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 30 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 35 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 40 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 45 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 50 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 55 Degrees Fahrenheit

Dual Lab Thermometers 60 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 60 Degrees Fahrenheit

Dual Lab Thermometers 65 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 65 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 70 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 75 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 80 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 85 Degrees Fahrenheit

Dual Lab Thermometers 90 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 90 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 95 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 100 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 105 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 110 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 115 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 120 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 125 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 130 Degrees Fahrenheit

Dual Lab Thermometers 135 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 135 Degrees Fahrenheit

Dual Lab Thermometers 140 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 140 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 145 Degrees Fahrenheit

Dual Lab Thermometers 150 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 150 Degrees Fahrenheit

Dual Lab Thermometers 155 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 155 Degrees Fahrenheit

Dual Lab Thermometers 160 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 160 Degrees Fahrenheit

Dual Lab Thermometers 165 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 165 Degrees Fahrenheit

Dual Lab Thermometers 170 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 170 Degrees Fahrenheit

Dual Lab Thermometers 175 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 175 Degrees Fahrenheit

Dual Lab Thermometers 180 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 180 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 185 Degrees Fahrenheit

Dual Lab Thermometers 190 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 190 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 195 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 200 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 210 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 215 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 220 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 225 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 230 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 235 Degrees Fahrenheit

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Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 240 Degrees Fahrenheit

Dual Lab Thermometers 245 Degrees Fahrenheit

Dual Lab Fahrenheit Thermometers

Dual Lab Thermometers 245 Degrees Fahrenheit