Detailed Instructions: In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Problem:Passage: Edward Page Mitchell (1852–1927) was an American editorial and short story writer for The Sun, a daily newspaper in New York City. He became that newspaper's editor in 1897, succeeding Charles Anderson Dana. Mitchell was recognized as a major figure in the early development of the science fiction genre. Mitchell wrote fiction about a man rendered invisible by scientific means ("The Crystal Man", published in 1881) before H.G. Wells's The Invisible Man, wrote about a time-travel machine ("The Clock that Went Backward") before Wells's The Time Machine, wrote about faster-than-light travel ("The Tachypomp"; now perhaps his best-known work) in 1874, a thinking computer and a cyborg in 1879 ("The Ablest Man in the World"), and also wrote the earliest known stories about matter transmission or teleportation ("The Man without a Body", 1877) and a superior mutant ("Old Squids and Little Speller"). "Exchanging Their Souls" (1877) is one of the earliest fictional accounts of mind transfer. Mitchell retired in 1926, a year before dying of a cerebral hemorrhage.
 Link Information: Originally serialized in Pearson's Weekly in 1897, it was published as a novel the same year.  Question: How much time had passed between the publication of "The Crystal Man" and the publication of The Invisible Man?
Solution:
Answer: 16