When the air in the singing tube is singing, it forces the gas in the jet tube to vibrate in the same period and in such phase that at the nozzle the pressure in both tubes shall be the same.
He then casts it into its final form through a nozzle in the bottom of the casting ladle, as in the Bessemer process.
Thus, at every complete stroke of the piston, the air in the vessel or receiver was diminished by that fraction of itself which is expressed by the ratio of the volume of the available cylindrical space above the outward opening valve to the whole volume of receiver, nozzle and cylinder.
If the jet tube is somewhat longer than half the sounding tube there will be a node in it, and now the condition of equality of pressure requires opposite motions in the two at the nozzle, for their nodes are situated on opposite sides of that point.
Dr Joseph Black's instrument consists of a conical tube of tin plate, with a small brass tube, supporting the nozzle, inserted near the wider end, and a mouth-piece at the narrow end.
To obtain a good reducing flame (in which the combustible matter, very hot, but not yet burned, is disposed to take oxygen from any compound containing it), the nozzle, with smaller orifice, should just touch the flame at a point higher above the wick, and a somewhat weaker current of air should be blown.
The water as it thus issues from the nozzle feels to the touch like metal, and the strongest man cannot sensibly affect it with a crowbar.
The most simple test for the value of a system of fire-proof coverings, and of partitions and furrings, is to erect a large sample of the work and to subject it alternately to the continued action of an intensely hot flame which is allowed to impinge upon it, and to a stream of cold water directed upon it from the ordinary service nozzle of a steam fire engine.
During the down-stroke of the piston the former was pressed home, so that no air entered the nozzle and vessel, while the latter was forced open by the air which so escaped from the cylinder.
The stream issues through a nozzle, termed a " monitor " or " giant," which is fitted with a ball and socket joint, so that the direction of the jet may be varied through considerable angles by simply moving a handle.
Or it may be revealed by placing a sensitive flame of the kind described below with its nozzle at the focus.
To give an idea of the force of the agent thus employed it may be stated that when an eight-inch nozzle is used under a heavy head, more than 3000 ft.
To get the best effect the area of the blast-nozzle must be properly proportioned to the size of the cylinders and be properly set with regard to the base of the chimney.
In the treatment of stiffened joints, massage under water is very serviceable, and in the so-called Aix douche a nozzle from which water continuously streams is fastened to the wrist of the masseur, so that a current of water is constantly playing upon the joint which he is rubbing.
It consisted of a spherical glass vessel opening below by means of a stop-cock and narrow nozzle into the cylinder of an "exhausting syringe," which inclined upwards from the extremity of the nozzle.