Setting the Ritual bowl with blackroot on fire

[Sarevok]

How?

[Shard of Manus]

Stick it on the grate in Siva's basement and turn the valve.

[DarkCobalt]

If you have any Pyromancy abilities you can plop items on the ground and light em up with spells.

[Vain]

You have to combine the bowl with the Blackfoot then click and brag the bowl on to the center of the fire forge from your inventory. Then click the lever.

[Phantomox]

the correct order is............
black root and bowl,lance on yourself,blooded lance with bowl,then throw it on the grate on the floor of the incinerator,hit the valve for the incinerator

[Bastila Shan]

There’s a book in the meisters basement that tells you what to do

Ps find more black root in the cloiser Woods