First, the extinguisher valve is removed and the threads and interior of the cylinder are checked for corrosion, pitting, and any other abnormalities. [29 CFR 1910.157(f)(3)] If the cylinder passes the visual inspection, it is placed into a steel chamber, which is then filled with water at normal pressure.
Updated April 17, 2017. The earliest dated printed book known is the Diamond Sutra, printed in China in 868 CE. However, it is suspected that book printing may have occurred long before this date. In 1041, movable clay type was first invented in China.
Johannes Gutenberg got rid of the woodblock ideas and tried to work with metal. He decided it worked very well and was completing the first book ever printed by his new invention, which was movable type. The first book was the Bible, which was printed in Latin. His invention was called the printing press. Soon enough the blacksmith that Johannes Gutenberg was working for lost faith in him and decided to take him to court. The judge favored with Fust, so everything Gutenberg worked on and owned belonged to Fust. Johannes Gutenberg ended up dying in Mainz, Germany in 1468.