It is precisely defined by a vibration number recording the frequency of the pulsations of a tense string, a column of air, or other vibrator, in a second of time.
5 The writer recommended the use of a flexible plate at the source of sound, which would vibrate in response to the varying pressure of the bons' air, and thus open and close an electric circuit, and of a similar plate at the receiving station, which would be acted on electromagnetically and thus give out as many pulsations as there are breaks in the current.
When the relay is operated it connects a bell between one of the wires of the circuit and earth, while the bell itself is arranged to respond to current pulsations in one direction only.
The lake is practically tideless, though true tidal pulsations amounting to 3 in.
It consists of a definite contractile sac or sacs lying on the dorsal side of the alimentary canal near the oesophagus, and in preparations of Terebratulina made by quickly removing the viscera and examining them in sea-water under a microscope, he was able to count the pulsations, which followed one another at intervals of 30-40 seconds.
Clinically it is to be observed that the drug is cumulative, being very slowly excreted, and that after it has been taken for some time the pulse may become irregular, the blood-pressure low, and the cardiac pulsations rapid and feeble.
To know the thoughts and deeds that have marked man's progress is to feel the great heart-throbs of humanity through the centuries; and if one does not feel in these pulsations a heavenward striving, one must indeed be deaf to the harmonies of life.