Round wick lanterns are considered a step up from their flat wick counterparts. While flat wick lanterns are usually intended for use outdoors and in sheds, outhouses etc, round wicks are made for being used in the manor proper.
This said, though they are invariably more expensive and the technology is seemingly more advanced than flat wicks, they don't give out that much more light. But if you use these rather than flat wicked storm lanterns in your parlor, you will give the impression that you have a degree of gumption and your ducks in a row.
After having used them for a while, the wick in these will end up being spent unevenly. Homo electricus will react to this by turning up the wick, leading to incomplete combustion, lots of soot and not noticably more light.
To trim a round wick, take the burners off their oil houses, and let the wicks dry out for a day. Turn up the wick until a millimeter of the wick's lowest part juts out, dip the protruding edge of the wick in kerosene and light it up. Let it burn out, any loose threads jutting up can be scraped away with a knife.
Gear for trimming below, the dish is for dipping the top ends of the wicks in.
In books written today but set in a a non-electrified place or period, one will sometimes read about lights being trimmed while in use. Even the otherwise very clever Philip Pullman makes this mistake. This is entirely normal. It only takes a couple of decades for one set of skills to be almost entirely lost.
There is currently an astonishingly harshly worded entry on kerosene lanterns on Wikipedia. The subject does bring out the activist in some.
See also on this site: Kerosene addiction I: Flatwick lanterns