The application of the cymometer to the determination of the coefficient of coupling of oscillation transformers, (Fleming) WITH The Production of Radium from Uranium (Soddy) EXTRACTED from The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, Volume 9, Series 6, 1905, pp. 758-767; pp. 768-779. J. A. Fleming, Frederick Soddy.

The application of the cymometer to the determination of the coefficient of coupling of oscillation transformers, (Fleming) WITH The Production of Radium from Uranium (Soddy) EXTRACTED from The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, Volume 9, Series 6, 1905, pp. 758-767; pp. 768-779

London: Alexander Tilloch, 1905. 1st Edition. FIRST EDITION (EXTRACTS) OF TWO PAPERS: J.A. FLEMING’S DETAILED DESCRIPTION OF THE CYMOMETER, HIS INVENTION OF AN INSTRUMENT TO BOTH EXHIBIT & MEASURE WAVE MOTION & SODDY ON THE PRODUCTION OF RADIUM FROM URANIUM.

In 1904 the English physicist John Ambrose Fleming invented and patented the cymometer (fequency counter), a convenient instrument for measuring the frequency of electric oscillations and the length of electric waves; a few months later (in a paper we offer separately, he invented and patented the Fleming, or thermionic valve). At a March 1905 meeting of the Physical Society, Fleming read the cymometer paper; it makes its first appearance in print here, in this 1905 Philosophical Magazine.

Dr. Fleming’s direct reading cymometer used the glow of a Geissler tube to indicate resonance and give a reading of wavelength on a calibrated scale. “The instrument consists essentially of a closed circuit containing a condenser and an inductance, the distinctive feature being the fact that the capacity and inductance are so arranged as to be varied simultaneously and in the same proportion by one movement of a handle” (Dyke, “On the use of the cymometer”, Phil Mag, 1906, 666). Because the cymometer, then, is essentially “an oscillatory circuit, the capacity and inductance of which can be varied, and are known at any instant. If, therefore, the cyclometer circuit is placed in contiguity to another circuit in which oscillations are taking place, the cyclometer constant can be altered until its circuit comes into tune with that of the circuit under test. This can be ascertained by the use of a neon vacuum tube connected to parts of the cymometer circuit, which glows very brilliantly when the current in the cyclometer circuit reaches its maximum value, in consequence of the cyclometer being as that moment exactly tuned to the circuit under test” (Engineering, Volume 86, 1908, 578).

Today, the cyclometer is generally referred to as “frequency counters” — “an electronic instrument, or component of one, that is used for measuring frequency” Frequency counters usually measure the number of oscillations or pulses per second in a repetitive electronic signal” (Wikipedia).

In 1904, Fleming began to consider how to improve the coherer that was being used for wireless communications and developed the “Fleming valve” and patented it as a replacement for the coherer. The Fleming valve was later developed by others for a host of applications from sound amplification to electronic switching in digital computers, and is now known as the “vacuum tube.”

ALSO INCLUDED, FREDERICK SODDY’S “THE PRODUCTION OF RADIUM FROM URANIUM” (pp. 768-779). This paper followed Fleming’s and is included as well. In 1903 and before they parted company, Rutherford and Soddy put forth their disintegration theory suggesting that uranium was the primary source from which radium was derived, understanding clearly that radium could not be a ‘permanent’ element. More than any other scientist of his time, Soddy imbued radium with lifelike qualities. The public, however, had taken things further, seeing the half-living element as not simply lifelike, but life-giving. “While Soddy had employed a discourse of living radium in no small measure to help conceptualize what was going on in the physical world, popular writers… brought about their own transmutation of radioactive discourse to ultimately grant radium a ‘vitalizing’, and not just a vital, character. Soddy had succeeded in bringing radium to life” (Campos, Radium and the Secret of Life, 51). Item #820

CONDITION & DETAILS: London: Alexander Tilloch. Extracted from The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, pp. 758-767 (Fleming) and pp. 768-779 (Soddy). (8.5 x 5.5 inches; 213 x 138mm). The plate that should accompany the paper is absent. The extract is bright and clean and in very good condition.

Price: $45.00