Nature's Operations which Man is competent to Study. 473 



Conclusion. 



No physicist can consult the diagram presented in fig. 1 

 without being struck by its resemblance to an absorption- 

 band in a spectrum. Nature is occupied in working every- 

 where over the entire spectrum ; man's knowledge of her 

 works is confined to what occurs within this one absorption- 

 band. How much changed would be the aspect under which 

 the human mind would have had to view nature, if the position 

 of the absorption-band had occupied a different place — if, for 

 example, the range of our knowledge had been Groups B, C, 

 D, and E, instead of A, B, C, and D ; with such a full 

 knowledge of molecular objects and events as we now enjoy 

 of objects that range from kllems down to microns ; and with 

 such a lessened knowledge of Group C as we now have 

 of planetary events ! An equally startling change would be 

 made if the range had been shifted the other way : if we had 

 no knowledge of microscopic or molecular events, just as we 

 now possess none of those which go on within and beyond 

 sub-section to of Group D ; if at the same time we had only 

 a smattering of knowledge about Group 0, such as the 

 fragments we are now able with difficulty to obtain about 

 Group D, accompanied, however, by some real acquaintance 

 with the immense universe that lies beyond Group A. 



Along with these considerations we should ever bear in 

 mind that behind and above the great universe of natural 

 objects, and the true cause of ail the rest, there stands the 

 Autic Universe, the mighty Autos, to which the present 

 writer endeavoured to draw attention in an earlier paper, and 

 of which the thoughts that are our real selves are part. 

 (See Scientific Proceedings of the Royal Dublin Society, 

 vol. vi. (1890) p. 475.) 



Appendix. 



A Standard Model of molecular phenomena is described 

 above in the footnote on p. 471. 



The writer can strongly recommend the corresponding 

 Standard Model of Celestial phenomena. This is made by 

 taking tenthets of all celestial distances and fifthets of all 

 periods of time. By this means, intervals which in Nature 

 have to be measured in Groups A and B of fig. 1, are repre- 

 sented on the model by the similarly situated measures shifted 

 one group to the right, i. e. the distances are to be read off in 

 Groups B and C instead of in Groups A and B. At the same 

 time all intervals of time and all velocities become on the 

 model the fifthet, or hundred-thousandth part, of what they 

 are in nature, so that a celestial velocity of so many kllems 

 per second takes the form in the model of a velocity of the 

 same number of centimetres per second. 



