Abstract: The invention is concerned to control the combustion conditions of a burner 1 supplied with a mixture of pulverized fuel and air. By use of a vortex amplifier 10 in the supply pipe 3, the supply of fuel is interrupted so that the flame is consequently first too lean and then too rich. The temperature of the burner flame is monitored by a photodiode device 6a and an indication is produced of the delay between the operation of the vortex amplifier 10 and the flame temperature passing through that indicating that the flame conditions are optimum. The length of the delay will indicate whether, and to what extent, the flame before the operation of the vortex amplifier was too lean or too rich. Adjacent burners can be controlled by operating the vortex amplifiers associated with each at different regular frequencies.

Abstract: An adjustable shower and massage apparatus adapted to be connected to water systems generally associated with bathtubs and stall showers. The apparatus is formed with a plurality of interconnected pipe members, the leading pipe member being attached to the water system and the trailing or end pipe being affixed to a stationary member such as a wall. The pipe members are interconnected by a plurality of universal joints which allow the contiguous pipe members and a connected shower-spray head to be positioned at any selected angular position, whereby water can be directed to any part of an individual's body, the apparatus including a handle for positioning the pipe members.