The Infusion Altar is the place where you craft many of Thaumcraft's more advanced items and blocks.
It is made by researching "Magical Building Blocks" and then crafting 4 Arcane Stone Blocks. You then place the 4 blocks on the ground in a 2x2 configuration, and right click on them with a Wand of the Apprentice.
The Infusion Altar uses the mechanics of both the Crucible and the basic Arcane Worktable. It has the usual 3x3 crafting grid, a large slot to its right for products, and a smaller slot underneath the output slot for a wand. It will act as an Arcane Worktable if appropriate ingredients are placed, and similarly to the Arcane Worktable, is quite capable of the duties of a normal crafting table.
Underneath the crafting grid is a horizontal strip. Here, the Infusion Altar will display the required list of aspects needed to complete the recipe that is currently placed within its grid, if one of its own, more advanced recipes is arranged. Each recipe requires its particular items as well as one or more aspects of Essentia. Essentia can be provided by Arcane Alembics (if more than eight essentias are present in it), Crucibles and/or Warded Jars, in any combination, placed within 5 blocks above or below and within 12 blocks north, east, south or west of the northwest block of the altar. Arcane Alembics do not provide their essentia unless they are used to inject their content into the crucible. Before those aspects are fulfilled, they will be very transparent, but with the fulfilment of the aspect requirements, the aspects will become solid, and a colored particle effect will link the source of essentia to the altar. The effect will travel through walls. Essentia requirements will only update if a wand is in the altar's wand slot.
Multiples of many items can be crafted at once, limited by stack size, materials present, Essentia available, and the vis charge of the wand being used. Right-clicking on the output slot will produce the maximum number of products according to the least of these limits. Any Essentia in crucibles beyond what is needed for that number of items will be dumped into attached alembics, or if there is no (or not enough) available space in alembics, lost as Flux. Essentia drawn from Arcane Alembics or Warded Jars will only be consumed as needed.
Here are some of the items that can be crafted on the Infusion Altar. Not all possible recipes are listed here, but this should give you an example. As always, consult the Thaumonomicon to find more recipes as you've uncovered them.
- Elemental Wands
- Golems of all kinds
Here's a video that shows how the Infusion Altar works: http://www.youtube.com/watch?v=RJknILUax2g