H. A. Newton — Fireball of January 13th, 1893. 171 



board Bidge or Ansonia a little more than ten degrees. (The 

 elevations of Ansonia, and Clapboard Ridge above the sea may 

 in this case be neglected.) The remaining condition is less 

 exactly determined by the observations. The best unknown 

 to use is the place of the meteor's quit, that ig, the point on 

 the celestial sphere from which the meteor was moving. 



35. A glance at the observations in and near Boston, and in 

 N. Y., shows that the meteor was moving in that plane at a 

 large angle with the vertical and also at a large angle with the 

 horizon. But no one of the observations has by reason of the 

 position of the observer, or other quality, a clear right to be 

 used to the exclusion of the others. 



36. The meteor's path is assumed to be a right line ; hence 

 its apparent path to each observer must be an arc of a great 

 circle on the heavens. The true path produced passes through 

 Clapboard Bidge ; the circle of its apparent path must contain 

 the point near the horizon in which Clapboard Bidge would 

 be seen by the observer. The apparent path produced back- 

 ward on the sky must contain the meteor's quit We must 

 determine on the photographed arc a place for the quit such 

 that the various observations shall be best satisfied, regard 

 being had to every known quality of the observations. 



37. An artificial globe (celestial or terrestrial) is convenient 

 for the study of the problem. Set the pole of the globe in 

 the zenith, and then the meridians are vertical circles. If the 

 statements of the observers are not definite enough (and they 

 are not in this instance) to make it worth while to consider the 

 different places of the zeniths of the observers, we may treat 

 the pole of the artificial globe as the zenith of each observer. 

 Then, the point on the horizon in the azimuth of Clapboard 

 Bidge from the observer must be in the circle of each ob- 

 served path. Assume on the photographed path a quit, and 

 suppose arcs drawn from this quit to the several horizon points. 

 If the quit is correct the observed paths were in these arcs. 

 Move the quit up or down the photographed circle until the 

 arcs represent the statements of the several observers with the 

 least violence to the language used. Instead of a globe a 

 stereographic or a central projection of a hemisphere may be 

 used. If the observations warranted greater refinement of 

 treatment methods of computing could be easily devised. I 

 find that if the quit is taken 45° from the line joining Clap- 

 board Bidge to Ansonia the various accounts will be satisfied 

 about as w r ell as if the quit was assumed to be at any other 

 point in the photographed plane. 



3y. The distance from Ansonia to Clapboard Bidge is 

 twenty-two miles and I assumed that the angle at Clapboard 

 Bidge is 45°. The length of the track on the photograph 



