In a book from 1835 on gun making, the author (W. Greener, C. E.) says one should special-request the barrel makers to cold-hammer the barrels for a half-hour after they are welded up, then he throws this in:
“A gratuity is, of course, expected, either of money or beer, and I believe a few pots of the blood of Sir John Barleycorn will infuse more strength into your barrels than you could purchase for ten times the amount in money, as it has the effect of making the hammer descend with increased velocity”