Is there any difference between the Balling scale and the Plato scale?

Balling is a standard for the measurement of the density of solutions expressed as a percentage of the weight of the solute on (grams of sucrose per 100 grams of solution). Degrees Balling (°B) is sometimes used as a substitute for degrees Plato (°P). However, the two are not equivalent since the Balling scale was calibrated at 17.5°C and not at 20°C as is the Plato scale.

The difference between the two scales is about 0.05% wt/wt units. Both degrees P and B are temperature dependent. Traditionally used in Europe, it has largely been replaced by the Plato scale.

http://www.beer-brewing.com/beer_brewing/about_this_title/glossary/beer_brewing_b.htm