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.
The most influential American novel ever written appeared first in weekly instalments between June 1851 and April 1852 in the National Era, a Washington DC periodical with an anti-slavery slant. It was a sensational success and when published in book form in 1852, sold more than 300,000 copies in the first year.