214 Outlines of Meteoric Astronomy. 



and that apparently a small one, every eighth year. The 

 ordinary, or general star-showers, on the other hand, compose 

 belts of vast extent, and must either be the embers of former 

 star-showers now absorbed by the earth, or else the original 

 distribution of meteoric matter round the sun in its primitive 

 unaffected order. We may suppose this matter to have been 

 in a state of dust or infinitesimal division, so that in general 

 the ordinary star-showers represent the primitive prevailing 

 currents. Occasionally, and at some places, the currents of 

 microscopic dust are found concentrated into shooting-stars ; 

 and these, by some unknown predisposing cause, have been 

 collected into star- showers. Finally, it would appear that fire- 

 balls themselves are nothing more than the compacted elements 

 of star- showers. 



(8.) On the morning of the 19th of October, 1863, a very 

 luminous fire-ball was observed at Athens, under highly 

 advantageous circumstances, by Dr. Schmidt, in such a manner 

 as to illustrate by a striking example the ordinary composi- 

 tion of these meteors. The fire-ball advanced slowly through 

 an arc of 80°, and during fourteen seconds it was kept in view by 

 Dr. Schmidt in the field of a comet-seeker telescope magnify- 

 ing eight diameters. The meteor appeared twin, or double, 

 followed by a multitude of lesser companions, all of these 

 advancing with parallel paths and drawing behind them parallel 

 trains of light. Similar followers were visible to the naked eye-, 

 in a striking manner, in the great meteor of the 18th of August, 

 1783. In Cavallo's drawing (taken near London), there are de- 

 picted eleven such; in Robinson's (Newark) nineteen; and in 

 Sanby's (Windsor Castle) there are thirty-eight followers to the 

 meteor. In ordinary cases they follow the body of light so 

 closely as to give the meteor an elongated appearance, com- 

 pared to a wheatsheaf, a fish, a ninepin, etc., but at other 

 times the meteor appears divided, double, or pursued by two 

 or three balls, as in the case of Pringle's meteor of 1758, and 

 the great meteor in America, on the 20th July, 1860. The 

 ordinary forms are kite-shaped, pear-shaped, or globular. 

 Besides the followers, a permanent streak often remains upon 

 the track of a fire-ball, either fading away quickly or con- 

 tinuing visible for many minutes after the disappearance of 

 the meteor. In the latter case it rarely remains straight, but 

 changes its shape and position very sensibly, like a cloud 

 transported by the wind. In all these respects, fire-balls re- 

 semble gigantic shooting-stars. 



(9.) The heights of eleven fire-balls in England, in the years 

 1861-2, were found to be from 102 to 30 miles above earth's 

 surface at the moments of first appearance and disappearance. 

 Nearly fifty fire-balls observed before the date in question 



