Through the years there have been different versions of this and I speak in reference to the glasses that were gimmicked for this effect as the method remains the same.
Beginning with a heavy glass mouth down on the table and empty hands the magician takes hold of the glass and immediately starts to produce one coin (half dollar size) after another from thin air and each one produced is dropped inside the glass giving the audible facet to the performance.
Coins not supplied as any half dollar size or smaller will do. The adhesive used in this glass construction has yellowed with age otherwise all in very fine condition including illustrated instructions.