What branch of science did Benjiamin Franklinwork on?

His invention of the Franklin stove and its commercial success moved him from printing to natural sciences in the 1740s. In 1746 he started his famous experiments in electricity. He discovered the course of storms over North America,the course of the Gulf Stream, its high temperature and the use of the thermometer in navigating it. He also discovered the powers of different colours to absorb heat.