Friedrich Gottlob Keller (27 June 1816 - 8 September 1895) was a German machinist and inventor, who (at the same time as Charles Fenerty) invented the wood pulp process for use in papermaking. He is widely known for his wood-cut machine (used for extracting the fibres needed for pulping wood). Unlike Charles Fenerty, F.G. Keller took out a patent for his wood-cut invention. Early life Keller spent his childhood and youth working for his father as a weaver and heddle-maker in Hainichen, Saxony (north-eastern Germany). But he was unhappy in this occupation since his interest was in machines. Keller carried with him an "idea-book", where he jotted down different kinds of machines. He had subscriptions to many of the leading publications on machines, and was well read in the sciences of mechanics. In his late years he recalled an article he read in his youth about the work of the French mathematician René Antoine Ferchault de Réaumur. He took great interest in Réaumur's works and was curious about his efforts to find a method for making paper from trees. Réaumur himself never pursued the idea (later saying in 1742, "I am ashamed not yet to have tried this [paper making from trees] experiment since it is more than twenty years since I have realized the importance of it and since I have announced it."). It was an idea that stuck with Keller. In 1841 the 25-year-old Keller jotted down in his "idea-book" ideas for a wood-cut machine that could extract the fibres from trees for use in pulped-wood paper making. Keller's invention Before wood pulp became widely available, paper was made from rags, which were a limited resource. In the 18th century French scientist René Antoine Ferchault de Réaumur suggested that paper could be made from trees. Though he himself never experimented, his theory caught the interest of others, namely Matthias Koops. In 1800 Koops published a book on papermaking made from straw. Its outer covers were made from trees. His method was not like Fenerty's (pulping wood); instead, he simply ground the wood and caused the particles to adhere. His book does not mention anything about wood pulping. From 1841 (after noting his idea), Keller worked eagerly on his wood-cut machine. He had spent most of his life so far working with his father as a weaver and heddle maker, and on the side attempting to invent all sorts