Meteorites to the Earth's Orbit. 5 



antly learned. But when the statements have come from per- 

 sons who saw the stones come down, they are usually of much 

 more value than similar reports about ordinary meteors. In 

 any case when the reports are single they must be taken for 

 what they are worth. I have plotted them as given. 



In several notable instances where there are full accounts I 

 have not been able to accept the conclusions heretofore arrived 

 at as to the direction of the meteor's path. Thus, Dr. Bow- 

 ditch made the path of the Weston meteor to be from north to 

 south and parallel to the horizon. I make it to have moved 

 from a point 1ST. 40° W., 35° high. The Cold-Bokkeveld me- 

 teor was described by Sir Thomas Mac] ear as moving from the 

 W.N.W. It apparently moved in the opposite direction ; that 

 is, from the E.S.E. The l'Aigle meteor was described by M. 

 Biot as moving from the S.S.E., whereas it is well nigh certain 

 that it came from the N.W. In like manner the Stannern 

 meteorite was assumed by von Schreibers to have come from the 

 N.N.W., whereas there are reasons of great weight for -believ- 

 ing that it came' from the opposite direction. I may add that 

 these and other like changes are not made under any pressure 

 or bias to prove my propositions. In fact three of the four 

 changes just named make the evidence for my conclusions 

 weaker instead of stronger. 



In the treatment of the observations several quantities have 

 been neglected as not large enough to be comparable with the 

 probable errors of the observations themselves. Thus the 

 effect of the earth's attraction in changing the direction of 

 motion, or what has been called the zenithal attraction of the 

 quit, has been allowed for only in a general way. So the 

 earth's quit and goal are treated as being exactly 90° from the 

 sun ; or, in other words, the earth's orbit has been treated as a 

 circle. In like manner the motion of the place of fall due to 

 the earth's rotation on its axis has not been taken account of. 



Having located upon the. chart the meteor's relative quit we 

 have next to construct its absolute quit. This evidently lies 

 on the great circle joining the relative quit to Q (fig. 1), which, 

 when the sun is at S is represented on the chart by a straight 

 line through Q, together with its corresponding line through 

 G. When the absolute velocity of the meteor oid in its motion 

 about the sun is given, the place on this circle of the absolute 

 quit can be determined by combining by the parallelogram of 

 velocities the motions of the earth and of the meteoroid. The 

 following table is an abstract of a larger one used in this reduc- 

 tion, and is constructed for the limiting velocities 1414 and 

 1-244: 



