Symbolism, Imagery, Allegory
When Brierly commits suicide by jumping ship, he leaves his pocketwatch hanging on the rail. Let's take a look at that scene:
'There's a funny thing. I don't like to touch it.' It was Captain Brierly's gold chronometer watch carefully hung under the rail by its chain.
'As soon as my eyes fell on it something struck me, and I knew, sir. My legs got soft under me. It was as if I had seen him go over; and I could tell how far behind he was left too.' (6.7-8)
We have to ask: if Captain Brierly was planning to commit suicide, why bother leaving his watch behind?
Here's a theory. Brierly is all about order, right? He has a strong sense of duty and honor, and he does the right thing at the right time and expects everyone else to do the same. But Jim's actions aboard the Patna have challenged that notion of order for him. The watch acts as a symbol of his old life, the one that can no longer exist in a world full of Jims, where things are murky and muddled.
His leaving his watch behind parallels what the novel does with time in general. Conrad has left behind the good old-fashioned business of writing things in chronological order. He jumps around in time with wild abandon, leaving no room for orderly folks like Brierly to figure out what's going on.
Lord Jim's fuzzy relationship to time foreshadows the Modernists' view of time as something murky, unclear, and relative. In Lord Jim, and in much of the modernist literature that follows it, time is experienced differently by different people, and it slows down or speeds up depending on a character's perception.