We often, however, find coppers so inaccurately gauged as to make a difference of 4 or 5 barrels or more. In following this rule, therefore, it is indispensably necessary that the copper should be accurately gauged. The simplest and best mode of doing so is to fill the copper brim full with water, and having found a cask which contains precisely 36 gallons, or a barrel of liquid, take out one of the ends of it; you must then procure an unmarked wooden rod, long enough to reach the bottom of the copper; a piece of board must then be placed on the top of the copper, stretching out so as to conduct the rod perpendicularly to the bottom. Great mistakes are often made by not attending to this rule. The copper must then be run off barrel by barrel, very accurately, and at every barrel the rod should be dipped to the bottom of the copper, and a notch made where the water cuts the rod, barrel by barrel. This gives an accurate dipping-rod for the wet dip, and by reversing it and placing a piece of cork as usual on the other end, We have a dry dipping-rod.
In small coppers for private brewings, the same rule may be adopted, by marking the rod at every 1, 2, 3, or 5 gallons, as circumstances may require.
