The word "mammoth" was first used in Europe during the early 17th century, when referring to "maimanto" tusks discovered in Siberia. John Bell, who was on the Ob River in 1722, said that mammoth tusks were well known in the area. They were called "mammon's horn" and were often found in washed-out river banks. Some local people claimed to have seen a living mammoth, but they only came out at night and always disappeared under water when detected. He bought one and presented it to Hans Sloan who pronounced it an elephant's tooth.