<p>A combustion apparatus is provided comprising a container (1) and an air tube (2) with an end (7) which dips below the surface (6) of a volume of water (4). Thus, upon application of a negative pressure differential between an outlet tube (3) and the surface (6) air is drawn through the tube (2) in order to create bubbles (11) at an end (7) of that tube (2). These bubbles (11) undergo catastrophic expansion in order to release water particles which are drawn into an entrained flow with air towards an inlet manifold or air intake of a combustion engine. These water particles in appropriate ratio facilitate more efficient combustion and therefore engine operation.</p>
