

ASTRONOMER ROYAL'S TIME 39 



is not particularly mysterious; it is well known both 

 from theory and experiment that the mass or inertia of 

 matter increases when the velocity increases. The re- 

 tardation is a natural consequence of the greater inertia. 

 Thus so far as bodily processes are concerned the fast- 

 moving traveller lives more slowly. His cycle of diges- 

 tion and fatigue; the rate of muscular response to stim- 

 ulus; the development of his body from youth to age; 

 the material processes in his brain which must more or 

 less keep step with the passage of thoughts and emo- 

 tions; the watch which ticks in his waistcoat pocket; all 

 these must be slowed down in the same ratio. If the 

 speed of travel is very great we may find that, whilst 

 the stay-at-home individual has aged 70 years, the trav- 

 eller has aged 1 year. He has only found appetite for 

 365 breakfasts, lunches, etc.; his intellect, clogged by a 

 slow-moving brain, has only traversed the amount of 

 thought appropriate to one year of terrestrial life. His 

 watch, which gives a more accurate and scientific reck- 

 oning, confirms this. Judging by the time which con- 

 sciousness attempts to measure after its own rough 

 fashion — and, I repeat, this is the only reckoning of time 

 which we have a right to expect to be distinct from 

 space — the two men have not lived the same time 

 between the two meetings. 



Reference to time as estimated by consciousness is 

 complicated by the fact that the reckoning is very erratic. 

 "I'D tell you who Time ambles withal, who Time trots 

 withal, who Time gallops withal, and who he stands 

 still withal." I have not been referring to these sub- 

 jective variations. I do not very willingly drag in 

 so unsatisfactory a time-keeper; only I have to deal 

 with the critic who tells me what "he feels in his bones" 

 about time, and I would point out to him that the basis 



