Diffusing heat, an Olde formula.

[rezaxis]

I was researching some possible ways to make a thicker bottom on by boiler to help prevent scorching of a future "on the grain" wash.

The only thing I found was this old thing written by an Alchemist about a thousand years ago!

Follows is a cut and paste of the text with my observations/questions in parenthesis:

>The best lute(I don't know what this meant then. Obviously not the instrument.) is made thus. Take of loam(earth in equal parts of sand, silt and clay) and sand tempered with salt water(sea water or salted water? does it matter?) which keeps it from cleaving. To these add the caput mortuary(crusty stuff from evaporating acid stored as it might have been back then?) of vitriol (sulfuric acid) or aqua fortis (nitric acid), and scalings of iron(rust or forging scale?), and temper(mix while heating?) them well together. This serves to coat retorts or any glass vessels that must endure a most strong fire, and will never fail if well made. Some add flax, beaten glass, and pots and flints, etc. <

I know there are some serious chemist types around here and I would like their opinions and translations of what I found. Maybe a real up-to-date formula with some ratios of ingredients for this mortar/concrete, whatever.