7 Of colours7 Of colours9 Of colours9 Of coloursOf coloursThe Newton Project Knowledge Graph2020-10-08Journal9 Of colours7 Of colours10 Heate a peice of steele glowing hot, hold it over some water untill it turne from a white to a red heate then immediately quench it so far as you would harden for if it be quenched sooner it will bee too brittle if later too soft. Then makeing the end bright hold it over a candle that the end may be halfe an inch out of the flame, or lay it upon a hot iron, & these colours will follow one another towards the end of it; viz: bright yellow, deeper & reddish yellow or sanguine, a fainter blew; & a deeper blew, If it be quenched in tallow when tis yellow tis fit for gravers, drills &c: If when the light blew is on it it is fit for springs for watches If when the deepe blew is on it, it will bee very soft. Continue reading…