In many places the pressure on the mains is insufficient to raise the water to the upper floors or through improperly designed systems of piping the pressure may be so diminished as to make the flow extremely weak or the difficulty in securing proper water supply may be due to inconvenient location with reference to water mains. _The automatic electric house tank pumping plant_ has been designed and perfected to meet these conditions; the electric plant is connected to some power or lighting circuit and provided with an automatic attachment requiring no more care than can be given by any casual attendant. Such an installation avoids the smoke, ashes, dust and objectionable odors that accompany steam or gas plants. The accompanying diagram shows the general arrangement of the automatic electric house system used with a tank in the upper part of the building and the pump in the basement or cellar. The operation is as follows: When water is being delivered to the tank, the float rises until the upper knob makes forcible contact with the switch lever, opening the switch and stopping the pump. When water is withdrawn from the tank, the float falls until the lower knob makes contact with the switch lever, which again closes the switch and starts the pump. The supply of water is thus maintained within the tank without the aid of an attendant. The accompanying illustration, Fig. 238, shows a Worthington house tank pump of 500 gallons per hour capacity belted to a General Electric direct current motor, the pump and motor being mounted on the same base. TABLE OF CAPACITY. ================+========+========+========+========= Diameter | | | | of Plungers | 2 | 2-3/4 | 3 | 3-3/4 ----------------+--------+--------+--------+--------- Length | | | | of Stroke | 4 | 4 | 4 | 4 ----------------+--------+--------+--------+--------- Revolutions | | | | per Minute | 45 | 45 | 45 | 45 ----------------+--------+--------+--------+--------- Gallons | | | | per Minute | 9.8 | 18.5 | 21.8 | 34.4 ----------------+--------+--------+--------+--------- Maximum Water | | | | Pressure in Lbs.| 150 | 75 | 60 | 40 ----------------+--------+--------+--------+--------- Gallons per Hour| 500 | 1,000 | 1,200 | 1,800 ----------------+--------+--------+--------+--------- Feet 1 H.P. Will| | | | Pump Against | 175 | 80 | 70 | 50 ----------------+--------+--------+--------+--------- Feet 2 H.P. Will| | | | Pump Against | 300 | 175 | 140 | 100 ----------------+--------+--------+--------+---------