Compression fountain and pump

50.2 x 30.8 (fountain)
Bronze and brass

INDEX 1788 : R.II.461

Fons aeneus magnus et firmus, in quo aer vehementer compressus ope Antliae nº 452 memoratae, egerit aquam ad magnam altitudinem.

A big, firm bronze fountain which, the air being very compressed with the help of the pump referred to in no. 452, makes the water issue forth at a great height.

40.5 (pump)
Bronze e latão

INDEX 1788 : R.III.452

Antlia aenea mayor, quae interdum munitur valvula coriacea, ad aerem comprimendum.

A bronze pump, larger, that sometimes is provided with a leather valve to compress air.

The compression fountain is composed of an inverted pear shaped bronze receptacle that is seated on a circular brass base. The upper part is adorned with brass, having a threaded hole in the centre through which a tube is introduced which almost reaches to the bottom of the fountain. The hole is hermetically sealed by a tap at the end of the tube, the tap being threaded into the hole mentioned above. The tap has a terminal, that on its removal leaves a free thread where a manual compression pump can be installed.

Before installing the tube, a quantity of water corresponding to two thirds of its capacity was placed in the fountain. After replacing the tube, the tap was attached to the compression pump. For this, the terminal was removed from the tap that had been previously opened, and the pump was installed. Then, the compression of the water and air contained in the fountain was carried out, afterwards closing the tap. The pump was then removed, and the terminal replaced on the tap which was opened again. As a result of intense pressure on the inside of the fountain, a jet of water was obtained that could reach a height of approximately 8 to 10 metres in optimum conditions.

From Colégio dos Nobres, catalogue n.º 449 the fountain and n.º 440 the pump.

Nollet, Jean-Antoine, Leçons de Physique Expérimentale, Paris, 1764, Vol. III, Leçon X, Pl. 3, Fig. 16 and 17.

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