Outdoor Galileo Thermometer

In his search for recording temperature with precision, Galileo Galilei (1564-1642)
discovered a fascinating method. He put 4-5 glass balls in cylinder filled with a
special liquid to indicate the accurate temperature. 

In liquid, solid substances with the same weight and size sink when temperature rises,
and they ascend when temperature falls. The glass balls differ in weight and
the density of the liquid means the lowest of the floating ball in the upper part
of the cylinder shows the accurate temperature.

The production of the thermometer is complicated and can only be made by hand. 
Each ball is attuned to exactly 1 degree. Two glass balls differ in weight by only
6/100g. Its accuracy and exclusiveness will no doubt give you a distinct thermometer.