John Frederic Daniell

John Frederic Daniell was a British chemist and physicist best known for inventing the Daniell cell, an electrochemical battery that produced a steadier and more reliable current than the earlier voltaic cell it replaced. His design separated two different electrolytes with a porous barrier, a solution that overcame the polarization problem which had limited the practical use of earlier batteries. Daniell was also a versatile instrument maker, inventing a dew point hygrometer and a register pyrometer used to measure high temperatures.