(10)They should see that quantities of spirit for which passes have been issued by the officer-in-charge are accurately measured out to the vendors and the strengths are, as nearly as possible, equal to those prescribed by the Board, maximum variation of actual issue strength being 0-3 degree proof where hydrometer is marked in one-tenth of a degree, or 0-4 degree where hydrometer is marked in one-fifth of a degree.
