The core of a pencil is made of graphite. Drawings are made by transferring graphite onto paper. Are there rules for this transference? Is a drawing acceptable if it shows only a smudge or a smear?  One manner to transfer graphite powder is through air pressure. A gun which can be armed with a firecracker creates an airflow when ignited. Because the back end of the barrel is closed off, the
air can only move forwards. The graphite in the barrel of the gun is then propelled at high speed. The result is a registration, a snapshot, of this explosive moment.