250 FROM NEBULA TO NEBULA 



netic disturbances on the earth, by tidal waves, by earth- 

 quakes, or by all of them together, and the causal connec- 

 tion has until now been one of complete mystery. It has, 

 indeed, been suggested that the sun at such crises is ex- 

 ceptionally charged with electricity and that this somhow 

 finds its way across the void ; but this idea is recognized 

 to be far-fetched even by its proponents. The true ex- 

 planation is this : 



Some sun-spots have been observed as much as five 

 times as wide as the earth, and there have furthermore 

 been witnessed from time to time solar eruptions upward 

 of 200,000 miles in height, with initial velocities exceed- 

 ing 100 miles a second. Such convulsions as these nec- 

 essarily portend a substantial displacement of the center 

 of mass of the sun and ipso facto of the entire solar 

 system, and cause perturbations to every individual 

 planet, satellite and comet within the latter, including, 

 of course, our earth. This is bound to be the case, 

 whether we view the planetary system in the conven- 

 tional light of Newtonian astronomy or in the new aspect 

 of an equilibrating unit. To make use of a homely 

 simile, the sun at such times is like a great spider in the 

 act of shaking his gravitational web. Now, (to change 

 the figure) although we, the passengers, on this great 

 ship may not be able to sense these perturbations direct- 

 ly, yet the earth herself does, and so while the solar con- 

 vulsion lasts, she gently wavers in her orbit and sways 

 upon her axis in rhythmical sympathy with her stricken 

 lord. The inevitable result is that the oceans are caused 

 to shake profoundly in their huge basins, producing not 

 only tidal waves, but also, by the friction on their beds, 

 augmenting the supply of electricity normally furnished 

 by the diurnal tides. The effect of these perturbations 

 on the solid parts of the earth is sometimes, though per- 

 haps not usually, accompanied by earthquakes. The 

 reason for this is not that the perturbations are the vera 

 causa of, but that they precipitate, earthquakes nearly 

 ripe for spontaneous manifestation, much as the slam- 

 ming of a door may cause the glowing coals of a grate fire 

 to collapse when near the point of doing so of themselves. 



