Abstract: An improvement in the implementation and employment of thermal-aerosol fog and/or smoke generating devices is disclosed wherein a pressurized source of an atomizable and/or vaporizable liquid is supplied in a visually monitorable and controllable or adjustable manner to an improved exhaust gas manifold wherein the liquid is mixed with and atomized and/or vaporized by the hot exhaust gases and thereafter supplied to a blower outlet area for dispersion. The thermal-aerosol generator allows the quick replacement of the pressurized liquid source when a liquid-gas interface is first observed, wherein the new pressurized liquid source may be clamped to the generator and flow therefrom commenced prior to the remaining liquid from the previous container having been exhausted, thereby providing a substantially continuous controllable fog and/or smoke flow despite replacement of the liquid source.