Book of old techniques & knowledge that would be useful for a PC

[StainlessSteelCynic]

A friend put me onto this, it's Barkham Burrough's Encyclopedia of Astounding Facts and Useful Information 1889.
Made for US citizens and having a lot of information that is more useful for US adventures, it also has a lot of info no longer useful for us in the modern world and a lot of recipes have ingredients known by older names (a web search can usually locate the modern name of the ingredient).

Articles of interest include a list of the relative hardness of common US timbers, gestation periods of common animals, the pounds of coal required steam of 1hp per hour and so on.
There's a lot of non-useful info to wade through but overall it has some benefit

Barkham Burrough's Encyclopedia