Karrusel: a revolving escapement that is designed to reduce position errors in a watch and is mounted in a carriage similar to that of a tourbillion but differs from it in its slower speed of rotation and in having the fourth wheel contained inside the carriage.

English watches with Guillaume balances are very rare. Dent and Frodsham used few, Northern Goldsmiths Co., Newcastleon- Tyne made a few in 1918, Dreyfuss Moise of London two in 1929. Samuel Smith and Stauffer Co. seem to be the two English companies that had most faith in the Guillaume balance.

The Guillaume Balance. Anibal acier au nickel pour balanciers, an alloy invented by Dr. Charles Edouard Guillaume, exhibits unusual properties, both in terms of thermal expansion and in changes in elasticity. Around 1900 Guillaume attempted to eliminate the so-called Middle Temperature Error caused by the fact that the change of rate in a timekeeper with a steel-brass bimetallic balance is approximately a linear func-tion of temperature, while the change of rate caused by change in elasticity of a balance spring is approximately a quadratic function. Thus, it equals zero at only two temperatures, causing secondary error. In 1899, Guillaume noted that steel with an addition of 44.4% nickel had a negative square coefficient of thermal expansion. Anibal, combined with brass in bimetallic laminae, makes expansion close to quadratic. Balances with bimetallic rims made of anibal and brass are usually called Guillaume balances.