Sir J. Larraor : Escapements and Quanta. 593 



Huygens) with a strong coiled spring or a suspended weight, 

 it goes on vibrating for weeks, absolutely regular in ampli- 

 tude and phase, picking up from the driving spring just the 

 small quantum of energy that is needed to maintain it without 

 disturbing it, each time the escapement is engaged. Now it 

 is Rutherfordian isotopic doctrine that an atom is made of 

 an outer shell of some kind, the seat of all its chemical and 

 radiant properties, linked up with a core, perhaps sheltered, 

 but anyhow too stiff' to reveal itself sensibly in physical 

 activities, except in the inertia that belongs to its structure. 

 The outer electron-system which emits the lines of a spectral 

 series (and determines chemical quality) stands for the 

 pendular system of the clock, which is maintained in absolutely 

 continuous vibration from the energy of the core, imparted 

 gently through an escapement action, this vibration lasting 

 for many periods, and renewed every time the core is wound 

 up by its entrapping a particle with its translator^ energy. 

 All which is parabolic, yet to a vivid imagination may be 

 fertile in analogy. A connexion between the feed of 

 energy and the free period (e=7iv) is, however, wanting. 

 Perhaps also the clock may be reversible, and by absorbing 

 incident radiant energy of proper periods into its pendular 

 system may wind up its spring — pointing ultimately to 

 instability and ejection of a particle from the core, in the 

 manner recognized. 



Such quantized, or as they would say in Edinburgh, 

 quantified, maintenance of a vibrating system is far from the 

 orthodox smooth vibrator, imported into the usual mathe- 

 matical theory of optics, but quite ineffective as regards 

 sharp selective spectra. But its case is not uncommon in 

 nature : a blown organ-pipe, or a bowed string, emits an 

 absolutely regular train of waves maintained as long as is 

 desired. And an escapement may be imagined as modified 

 into a smooth continuous mathematical mechanism of con- 

 straint, working without any jerk. Ought one to consent to 

 be driven, even under many-sided compulsion of facts, to intro- 

 duce such discontinuous gear as a feature in diagrammatic 

 representations of nature's hidden mechanism of selective 

 radiation ? 



But may there be an alternative to such creation of natural 

 quanta of a sort through mechanism, — to the regular breaks 

 of continuity, however slight and gentle, that are perhaps 

 essential to escapement action ? One recalls that in the 

 usual periodic vibrating atomic system illustrative of optical 

 theory, each free period is independent, and its own energy 

 fades away by radiation, no transfer or feed of energy from 



