MATTER AND ENERGY. 45 



rences taking place with such regularity that there 

 must be some system in the display. On the 10th of 

 August and the 13th of November, " star showers " 

 may be expected and looked for every year. On al- 

 most any clear night a " shooting star " may be seen, 

 therefore the earth may be gradually gaining at the 

 expense of meteoric substance. That showers of aero- 

 lites are encountered on certain days in the year would 

 indicate that their concurrent course is in proximity 

 with the earth's orbit; and that their velocities are re- 

 lated to the speed of the planet's movements. Mete- 

 orites are dark bodies and are not seen if they strike 

 the earth in the day time. However, a meteor of 

 considerable size might strike near an observer, and 

 make its presence known by hissing sounds and a puff 

 of smoke where it hit. A number of such bodies are 

 to been seen in cabinets. When critically examined 

 they present no elements not found in our planet, 

 therefore, it is presumed that in " other world's than 

 ours " there is nothing new. Meteors become incan- 

 descent through friction as they reach the denser por- 

 tions of our atmosphere, though the luminosity is not 

 pronounced enough to be seen in the light of day. 

 The cause of the collision is not a fortuitous circum- 

 stance, but the impact is mostly produced by the at- 

 traction of the immensely greater body by the gravi- 

 tating power of the earth. 



The subject of meteors is introduced to illustrate 

 what may be said in regard to the nebular theory, so 

 called, which supposes that matter in an exceedingly 

 tenuous state once pervaded all space, and afterward 

 became aggregated into prodigiously great masses that 

 have been denominated solar systems, our own being 

 one of the smallest of the entire lot. In the contem- 



