Benjamin Franklin is one of the best known but least understood of America's revolutionary generation. He is well known to schoolchildren around the world as one who dabbled in the arts and sciences so as to invent bifocals and glass armonicas, refine the draft pipes and dampers of stoves, and develop and foster public libraries, in addition to savings, insurance, and fire companies. Journalists and those who enjoy the craft of printing honor Franklin as a central figure in the formation of printing and communication networks that afforded communication among the British colonies of the eastern seaboard of North America. Numismatists celebrate Franklin as the first Postmaster General in the colonies. Graphic artists and those who like to collect coins and engravings value Franklin's work as an artist of political satire and an engraver of iconographic emblems representative of American materials and concerns. Indeed, Franklin has great significance in a long tradition, from medieval times, of emblem-makers. Farmers and those who read almanacs recognize Franklin as the founder of an almanac tradition in British North America. And scientists and those who study the thermodynamics of the atmosphere in order to make predictions of significant weather events honor Franklin for making the final determination regarding the positive and negative currents behind electricity, for measuring the ocean temperatures, for determining the impact of volcanic eruptions on the weather patterns in places far distant, and for charting the Gulf Stream.