This has been discussed in another thread, but since Emelric pointed out that this is where it ought to be discussed, I'll summarise here.
Income proposal: salt extraction
Salt sells at £120 per metric ton [Cov], and it is a very convenient merchandise in the high price/weight ratio and the fact that it does not go bad. The main obstacle to mundane extraction is the fuel required to boil seawater. (Elsewhere in the world, sunshine may solve that problem, but we are in Cumbria.) Secondly it is regarded as labour intensive. This is a good case for using magic. Here are a couple of alternatives. I am assuming seawater with 3½ kg salt per 100l water.
- Spell casting.
ReAq4 (touch range) evaporates the water, leaving salt behind. Let the grogs fill a 1000l basin with seawater, and a magus can quickly cast the spell for about 35kg salt. Repeat this ten times a year for 350 kg or £40 worth. Grogs can scrape out the salt for shipment.
The down side is that Dex+Finesse 12+ is required to get proper quality. We may have to make 100 attempts to get 10 of salesworthy quality. Although the exact mechanics can be negotiated according to Emelric. Second downside may be the potential botches if the spell is spontaneous, but inventing it is only a season.
I have not scrutinised all the magi's stats, but my impression is that none of us have the Dex+Finesse to make this worthwhile. If anyone thinks their magus could do it, we should make the calculations.
- A simple magic item
This requires some seasons invested to get started, but can then be run by the grogs.
Magnus crafts a leather bucket with the same effect as described above (ReAq10 for 50x/day).
Lignarius reads finesse for a season to raise from 2 to 3.
Lignarius takes a season to teach finesse to a dexterous grog.
Assuming the grog has Dex +1 and get Finesse 1, he will roll 12+ 10% of the time.
Fifty bucket per day would give five good buckets on average, or 1¾ kg.
This is only about 2h work per day (comfortable living for a grog), and repeating it six days a week year'round gives more than ½ton or £60 per year.
I am not sure what we would do about the 5 tons of bad salt, but as the grog improves his finesse, this amount will be reduced.
- A mundane craftsman with magic items
If we can recruit a salt crafter, maybe in France, we can create magic items to speed up his production.
Magus can create
a. A barrel similar to the bucket above, but evapourating only 90% of the water, to get concentrated brine. If we need an extra magnitude to do this, we can drop to 24 uses and it is still level 10.
b. A self-heating open pan (CrIg10) which the craftsman can use as if it were heated on open fire.
I reckon the hard part of this would be to recruit the craftsman. This does take more man power than alt. 2, but probably better quality salt if it matters. I do not really know how much salt one could produce per day, but I would be surprised if we cannot match the £60 of alt. 2.
** Scalability
Personally, I would aim to make £40 per yer on this trade. That makes a low footprint, with little risk to inflate the market. We can almost certainly produce more, but that would take a bit of research into plausible salt consumption and probably stories to make contacts to sell further afield. We really do not want to sell so much that we attract attention. Diversifying income is a help to go under the radar. If we go for a large operation it should be built up gradually.