This mathematics ClipArt gallery offers 8 images of thermometers, including illustrations of combination Celsius-Fahrenheit thermometers.
"Three temperature scales compared against one another." -Comstock 1850
A Centigrade and Fahrenheit thermometer side by side
An instrument for measuring temperature, founded on the principal that changes of temperature in bodies…
Fahrenheit thermometer at 41 degrees. Blood heat, water freezes, and zero are all marked on the right…
A thermometer showing both Fahrenheit and Centigrade scales.
"Thermometers showing the corresponding points for water's freezing and boiling." -Avery 1895
"Mercurial thermometer." — Waldo, 1896
An illustration of thermometers in Fahrenheit and centigrade/Celsius with freezing and boiling labeled.