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BELL SYSTEM TECHNICAL JOURNAL 



platinum cylinders each 1 mm. long - and 0.5 mm. thici<, while Nichols 

 and Tear in 1922 succeeded in making and using tungsten cylinders 

 0.2 mm. long and 0.2 mm. thick. To appreciate this feat it is neces- 

 nary to realize that the cylinders must be sealed into a sheet of glass 

 with both ends projecting; as they are shown in Fig. 1, which like the 

 remaining figures (unless otherwise mentioned) comes from the 

 work of Nichols and Tear. 



In Fig. 1, the oscillator-cylinders are shown at c and Ci; they are 

 sealed into the tips of hard-glass tubes 7" and Ti, and project outwards 



Short £/eclric (*6>i? Cer<erjlor 



M 



viAet resistance 





\ esaliotoi 



Sketch of oscillator. 



Fig. 1 — Diagrams of the Oscillator and the Circuit Used by Nichols and Tear. 

 (Physdcal Review) 



into kerosene oil which fills the entire cylindrical containtr up to the 

 level indicated by the dashed line.' The oscillator is excited by the 

 voltage-impulses in the secondary of an induction-coil, resulting from 



' The figure given by Mobius is 1.98 mm. (last column on p. 317, l.c.infra) which 

 he says (on p. i02) applies to the Gesamtlange of the doublet. Theory indicates 

 that the wavelength of the fundamental oscillation is about twice the length of the 

 cylinders, but the e.\act value of the factor is in doubt. 



»The kerosene, the "oil-jet" for keeping it circulating rapidly through the region 

 between the cylinders and the blasts of compressed air into the tubes T and 7'i 

 (note the spark-gaps in the le.iding in wires in these tubes) are all empirical devices 

 for improving the efficiency of the apparatus. 



