88 report — 1879. 



an explosion was audible at this place (near, but in advance of tbe meteor's 

 termination), which seems to be confirmatory of the view, elsewhere ex- 

 pounded, that the sudden concussion of a meteor-clap is not the conse- 

 quence of a disruption, but a cumulative sound, or combined acoustic 

 effect, at places near to and on one side of the meteor's course, of the 

 sound produced, and reaching an observer simultaneously from long tracts 

 of its fiery passage through the air. 1 Regarding the meteor's course 

 (apparently, from Mr. Walton's description, indoors, of the moving light 

 and shadows, at Cheboygan) as a steeply descending one, Professor 

 Kirkwood is led, roughly, to the following general conclusions : — The 

 fireball first came in sight nearly 100 miles over a point about 30 miles 

 S.W. of Great Traverse City (at lat. 44° 25', long. 9° W.), and it disap- 

 peared about 26 miles above a point about 42 miles N.E. by eastwards 

 from that town. The whole visible track was 124 miles, and its projection 

 on the earth's surface 66 miles in length from a direction S.W. by S. 

 towards N.E. by N. Of the time of flight, which was described as several 

 seconds, and of the real velocity, except that the observations indicate a 

 rather slow motion, nothing very definite can be affirmed. 



The altitude of the radiant-point appears from this description to have 

 been about 55°, and from the course, 33^° W. of S., from which it was 

 directed, the meteor's radiant-point may be assigned provisionally at about 

 142° + 14° ; but this cannot evidently be regarded as an exact determina- 

 tion. It is close to the border-line dividing Leo from the constellation 

 Cancer, and a suspicion may perhaps be entertained that, like the fireballs 

 above described, of January 12, 1879, and January 19, 1877, this imposing 

 aerolitic meteor of January 27-8, 1879, may have been a conspicuous 

 member of one of the ' Cancrid ' meteor systems which have been recog- 

 nised as discernible in December, January, and February, and as apparently 

 concentric in the first and last of those months with the hypothetical 

 radiant-points of the comets of 1680 and 1833. 



1879, February 22, 12 h 20 m a.m. Detonating meteor ; Essex. — Ac- 

 cording to the descriptions at Haverhill and Saffron Walden, two towns 

 scarcely ten miles apart east and west of each other, on the northern con- 

 fines of Essex, that the meteor passed from south to north between them 

 with a prodigious light and a report like thunder, audible in 20-45 seconds, 

 going east of the zenith to an end-point in N.E. at Saffron Walden, and 

 going overhead and down to N.W. at Haverhill, as the height above these 

 towns corresponding to the sound interval is only six or eight miles, the 

 meteor's track, at its close near them, cannot have extended many miles 

 northward of their position into Cambridgeshire. A height of five or six 

 miles nearly vertically over Newmarket, about eight or ten miles north of 

 Haverhill, must be the utmost height and distance northward from that 

 town at which the final disappearance of the fireball can be supposed to 

 have occurred, if the time interval at the former place and at Saffron 



1 The example of the detonating fireball of April 2, 1878, seems to be a parallel 

 one to the case of the present meteor. The sound of its extinction and nearest 

 approach to the earth, about 25 miles from Birmingham, towards which town its 

 course was nearly directed, was not perceived there, although at the greater distance 

 (about 30-35 miles) at which the meteor passed, when nearest, by the town of 

 Leicester, a sound like thunder, attributed to the meteor, was heard at that place by 

 Mr. F. T. Mott. The observer at Galashiels on May 12, 1878, also heard a peal of 

 thunder, apparently proceeding from the fireball of that date, no sound of which was 

 heard in Edinburgh or Bathgate, nearly over which towns the meteor disappeared. 

 See the last volume of these Keports, for 1878, pp. 305, 306. 



