Abstract: A drainage system for a synthetic sports field is disclosed that substantially prevents the leeching of specific contaminants from surface runoff water from entering into water tables or sewer systems associated with the drainage of the synthetic sports field. The drainage system includes a containment system and filtration system located beneath the synthetic sports field for directing rainwater through a series of drains and filters prior to being exposed to either the sewer system or water table. In this way, environmental concerns associated with the drainage of synthetic sports fields is alleviated.

Abstract: An indicator device to directly determine the efficiency of an external combustion apparatus such as a boiler. The face of the indicator includes an efficiency scale which has been preselected for the particular boiler apparatus based on the percentage of discharge of carbon dioxide within the combusted gases. The indicator measures the temperature of the combusted gases and through a movable pointer indicates directly the efficiency of the combustion process by the position of the pointer with respect to the face of the indicator. The indicator uses a second pointer which is to register and remain fixed at the minimum operating efficiency of the boiler.