432 POPULAR SCIENCE MONTHLY. 



length and one mile wide near Forest City. Iowa, in 1890. Many oi 

 these falls have been marked by extraordinary phenomena of light and 

 sound, making them events never to be forgotten by those who wit- 

 nessed them and worthy to be reckoned among the most remarkable 

 natural occurrences of the century. About two hundred and eighty-five 

 actually observed meteoric falls is the total recorded during the century. 

 It is a remarkable fact regarding the nature of the material fallen that 

 only five of these have been of meteoric irons. One of these irons fell 

 at Mazapil, Mexico, during the star shower of November, 1885, at the 

 time when the return of Biela's comet was looked for, and was thus con- 

 sidered an occurrence corroborative of the already suspected relationship 

 among comets, shooting stars and meteorites. 



The indifference to the collecting of meteorites which characterized 

 the early part of the century has given place in its latter days to an 

 extraordinary diligence in the search for these bodies. One meteorite 

 has of late acquired a value equal to four times its weight in gold and 

 several can be sold for two and three times their weight by the gold 

 standard. The meteorite collection of the Natural History Museum in 

 Vienna has for many years been the leading one. What it has cost to 

 build it up may be known from the fact that it is considered the most 

 valuable of any single collection in that great treasure house. Repre- 

 sentatives of over five hundred meteoric falls are exhibited in this col- 

 lection, and the meteoric matter has a total weight of seven tons. The 

 collection of the British Museum of Natural History is nearly as large, 

 while at Paris, Berlin, St. Petersburg and Calcutta, together with Wash- 

 ington, Chicago, Cambridge and New Haven, in our own country, are 

 gathered extensive and important collections. The establishment of 

 such large collections has for the first time put the study of meteorites 

 on a satisfactory basis and given lively hope that important truths will 

 be discovered by researches thus made possible. The general similar- 

 ity of the stony meteorites to the basic volcanic rocks of the earth has 

 been established, and similarity of many physical structures such as 

 brecciation, slicken-sided surfaces and veins has been proved. The 

 chondritic structure and the crystalline structure represented by the 

 Widmanstatten figures are, however, so far as is yet known, peculiar to 

 meteorites, and it will remain for the twentieth century to discover what 

 these structures mean. Classifications of meteorites based on their 

 mineralogical and structural characters have been established, and 

 important differences among meteorites shown, in spite of their family 

 resemblances. It would be idle perhaps to recount, as might be done, 

 many theories regarding the nature and origin of meteorites which have 

 been found untenable as a result of the century's study. The theory 

 of the lunar origin of meteorites had at times such able supporters as 

 Laplace and J. Lawrence Smith. Other able observers have believed 



