314 report— 1878. 



Iessthan50or 60 miles above the earth's surface, andata distance from Man- 

 chester of not less than 60 miles. The end point of its flight was about 

 30 miles distant from Manchester. An observer there (' V. R. ' 'Man- 

 chester Courier,' August 5th, 1878), describes its light during this last 

 most effulgent part of its course as " equal to the electric light at Belle 

 Vue when you stand 30 or 40 yards from it, on the far side of the plat- 

 form ; quite as much I should say." At 45 miles instead of 35 yards the 

 fireball must have shone with the brilliancy of (2,263 2 ) or 5,121,169, such 

 electric lights ! We may, perhaps, assume that for three seconds it illu- 

 minated Manchester with a glare equivalent to the mechanical strength of 

 something less than half this number of horse-powers, expending therefore 



X i — - — ' foot-pounds, or 4,224,964,425 foot-pounds of energy 



in its brief career ! Moving with a velocity of 25 miles per second, a 

 single pound- weight of matter possesses 270 - 555 millions of foot-pounds 

 of energy of motion, so that to account for the fireball's expenditure of 

 4,225 millions of foot-pounds of energy, it suffices to suppose that 

 4,225-^-270§, or 15'616 lbs. weight of matter composing its substance was 

 brought suddenly to rest by the enormous force of resistance of its 

 collision with the air ! Tbe average pressure of this resistance in a flight 

 of 70 miles must be 4,225 millions-:- (70 X 5280), or ll,4311bs., and this 

 pressure of nearly five tons against its front surface would instantly com- 

 minute and disperse any liquid or pulverulent substance, making it 

 obvious that the masses of shooting-stars, and of very luminous fireballs 

 like the present one, are really hard and compact stone, exactly as we find 

 those of aerolites to be. 



The intensity of the fireball's incandescence or ignition seems to have 

 been rather remarkable, as the light which it cast was bluish, and was 

 everywhere compared (about Manchester, at Conway, in Wales, &c.) to 

 sheet lightning, to the electric and limelights, and to daylight. It is, 

 therefore, not at all improbable that its powerful glare may have been 

 generated from a much less expenditure of mechanical energy than that 

 here represented, and that not only the mechanical action but also the 

 weight of meteoric substance, and the pressure on its surface here 

 supposed may be somewhat overrated. The nucleus nevertheless under- 

 went progressive disintegration all along its track, leaving a long string 

 or stream of countless red sparks, stars, or beads of fire in its wake, which 

 remained visible for a short time after the meteor's disappearance. It 

 did not bnrst and fly to pieces at last, but collapsed and disappeared 

 rather suddenly, and at places near which it descended to no great 

 distance from the earth no sound of any audible report following its 

 extremely brilliant flashes seems to have been perceived. 



III. Meteoric Showers. 



Somewhat plentiful displays of meteor showers, both occasional and on 

 the well-known annual dates, have been recorded during the past year, a 

 list of which is here appended where the date and the frequency of the 

 meteors and the position and accuracy of their radiant point were suffi- 

 ciently remarkable to make the observations of special interest, or of any 

 particularly new and significant importance. With the exception of a 

 few contemporaneous and foreign observations, they are almost all 



