from Mazapil, Mexico. 51) 



planetary space ( — 200"^ V.), compress the air strongly, and becom- 

 ing heated their wsp 'ed rapirlly diminishes to between 500 and 

 1200 metres. ThiM-e is rlurefore a greit amount of momentum 

 lost apparently ; one ])ortion has been nsed in compressing the 

 air and the other has been turned into heat, — the temperature 

 of the l)ody increasing up to 2000-3000°. If the meteor be small, 

 it will be entirely vaporized in the highei" atmosphere ; but if the 

 mass be great the outer portion only will be volatilized, and the 

 remainder will stiike the earth's surface before being entirely 

 burned away. As these bodies fall lower and lower into the 

 more dense atmosphere their velocity diminis'ies proportionally, 

 so that, upon striking the earth, they fall at the rate of 80-50 

 metres per second. We therefore perceive it to be [)ossible for 

 many meteors to fall upon the earth before being en ii-ely dissi- 

 l)ated, since ir all depends upon the size of the mass. 



As the greater portion of Biela's comet is now in smtill fi'ag- 

 ments, with here and there a larger one, as our observations 

 have proved, it is a i)erfectly possible occuiTence for some of 

 these to fall upon the earth before being entirely dissipated. 



I have stated already that in the Bielid shower of 1872, the 

 Abbe ^ecchi saw many spherical meteors, and Lemoisy, at Macon, 

 saw a sphere disappear in the horizon behind a house-to]). Many 

 observers saw, in 18^^5, spherical meteors quite close to the earth 

 although they were not seen to strike. By all these data jnid ob- 

 servatii/us \\q learn of the great importance of the Uranolite of 

 Mazapii. 



The ve]-y circumstantial st(U'y of the fall of this meteorite, 

 coupled with the lelative observations of the Bielids at Zaca- 

 tecas, is intere^ting in the exti-eme, and we can scarcely dis- 

 connect the two occurrences ai a mere coincidence. 



Xo explosion, ;is is usual when meteorites fall to the earth, 

 was heard by Sr. Mijares, or his neighbors, but in this particu- 

 lar similar cases could be cited. Very probably the explosion, if 

 there was one, occurred high in the atmosphere and at a great 

 distance from Mazapii. ^' The aerolite which fell at Stalldalen, 

 Sweden, at 11. 50- A. M., on June 28th, 1876, was visible as a 

 meteor over a great part of Sweden. It appeared as a large pear- 

 shciped mass, of a blinding whiteness to some, and of a fiery-red 

 toothers. It emanated from a })oint in Cepheus, and became 



