I'm not challenging your statement, but I wanted to add another
light source used before and during the American Civil War ... pine
knots. Jefferson, Texas was, at one time, a port city. Steamboats
traveled up the thru various rivers, bayous and creeks to the Big
Cypress river an into Big Cypress Creek to dock in Jefferson. Later
tha US Army Corp of Engineers, blew up a natural damn an drained the
water so low, that the steam boats could no longer travel that far
inland.
They have worked to preserve this old part of Jefferson and use the
same pine knot street lamps. Back during that era, a know in a picec
of wood made it inferior, so the knots were collected an burned in a
container, much like you would charcoal. The gas coming out of the
container, was piped to the street lamps. I don't think they use
pine knot gas now, but have switched to natural gas. It took me a
while to find out how pine knots could be made into gas, then I
remembered making charcoal in chemistry class and burnin the gas
that came out of the flask. The wood inside never caught fire and
didn't leave any ash.
Wow ... all that explanation to get to my point. I have to wonder if
those steam boats might have used such for lights. It seems that it
would be very easy to add such a chamber to the boiler fires. While
there is surface coal in east Texas, wood was much more plentiful.
I've met old timers that told me they have seen several entire city
blocks covered with cord wood just to fire boilers in railroad
locomotives, before they ventured into the barren western parts of
Texas. One of em told me that the area around this one small town
had been heavily forested in oak trees before the railroad burned
all of it. ...

) TEX