Dream premonition brother's murder

How can a captain of ship out at sea, many miles from land, know of his brother's murder back home in Cornwall?
We are not talking about a time when it is easy to have ship to shore communications and news can be sent from one place to another in an hour but of a time of sailing ships.

Captain Edmund Norway was aboard the ship Orient, outward bound from Manila to Cadiz, he had just finished a letter to his brother so knew the date of his premonition, 8th February 1840.
After writing the letter, he went to sleep, where he dreamt of his brother's murder. It was quite detailed, and so shocked him that he mentioned it to his second officer Mr Henry Wren, that he had dreamt of the murder of his brother Neville by two men. He even told him of the location.

By the time the Orient arrived back in England, Edmund Norway was to be proven right in his premonition, and two brothers were awaiting trail for the murder.
William and James Lightfoot were tried, found guilty and hanged for the murder.


The Norway's were ancestors of the writer Neville Shute.

www.nevilshute.org/Reminisces/ShirleyNorway1.php

archiver.rootsweb.ancestry.com/th/read/CORNISH/2006-07/1151869185 - 10k

Thats interesting because like you say there were no quick communications at that time you were on the ship untill you reached land and then your letter would have to travel for many weeks or sometimes months depending on where you were etc.