When people ask what you learned today... Manure... An interesting fact... Manure : In the 16th and 17th centuries, everything had to be transported by ship and it was also before the invention of commercial fertilizers, so large shipments of manure were quite common.
It was shipped dry, because in dry form it weighed a lot less than when wet, but once water (at sea) hit it, not only did it become heavier, but the process of fermentation began again, of which a by product is methane gas of course. As the stuff was stored below decks in bundles you can see what could (and did) happen. Methane began to build up below decks and the first time someone came below at night with a lantern, BOOOOM!