-15 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

-15 Degrees Celsius Centigrade

-20 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

-20 Degrees Celsius Centigrade

-25 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

-25 Degrees Celsius Centigrade

-30 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

-30 Degrees Celsius Centigrade

-35 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

-35 Degrees Celsius Centigrade

-40 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

-40 Degrees Celsius Centigrade

5 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

5 Degrees Celsius Centigrade

10 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

10 Degrees Celsius Centigrade

15 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

15 Degrees Celsius Centigrade

20 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

20 Degrees Celsius Centigrade

25 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

25 Degrees Celsius Centigrade

30 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

30 Degrees Celsius Centigrade

35 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

35 Degrees Celsius Centigrade

40 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

40 Degrees Celsius Centigrade

45 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

45 Degrees Celsius Centigrade

50 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

50 Degrees Celsius Centigrade

55 Degrees Celsius Centigrade

Dual Outdoor Celsius Centigrade Thermometers

55 Degrees Celsius Centigrade

An illustration of a two person file military formation.

Two Person File Military Formation

An illustration of a two person file military formation.

Two young boys sitting near a river bank hand washing dishes. There is also another figure in the background approaching with more dishes.

Two Boys Washing Dishes in a River

Two young boys sitting near a river bank hand washing dishes. There is also another figure in the background…

"...represents two wave systems of equal periods and amplitudes but of opposite phases." -Avery 1895

Waves with Equal Periods and Opposite Amplitudes

"...represents two wave systems of equal periods and amplitudes but of opposite phases." -Avery 1895

"The next simple mechanical power is the wedge. This instrument may be considered as two inclined planes, placed base to base." -Comstock 1850

Wedge

"The next simple mechanical power is the wedge. This instrument may be considered as two inclined planes,…