178 Field Museum of Natural History — Geology, Vol. III. 



13. Canyon Diablo. Florence: Am. Jour. Sci., 1895 (3)' xlix, 105. Thin 



tin-white, flexible plates. Calculated to 100 after deduction of 3.60% 

 schreibersite. 



14. Wichita Co. Cohen and Weinschenk: Ann. Wien Naturhist. Mus., 1891, 



vi, 155. Isolated by dilute HC1. Calculated to 100 after deduction of 

 schreibersite. 



15. Chupaderos. Manteuff el : Ann. Wien Naturhist. Mus., 1892, vii, 150. 



Brittle, tin-white plates. Isolated by HC1. Calculated to 100 after 

 deducting schreibersite. 



16. Toluca. Cohen and Weinschenk: Ann. Wien Naturhist. Mus., 1891, vi, 



137. Tin-white, flexible plates. Isolated by HC1. Calculated to 100 

 after deducting schreibersite. 



17. Canyon Diablo. Fahrenhorst: Ann. Wien Naturhist. Mus., 1900, xv, 



376. Thin, flexible plates partly appearing made up of many lamellae, 

 light-yellow or grayish. Schreibersite, 2.34% deducted. 



18. Glorieta Mountain. Cohen and Weinschenk: Ann. Wien Naturhist. Mus., 



1891, vi, 137. Tin-white, flexible, grouped plates. Isolated by HC1 

 Calculated to 100 after deducting schreibersite. 



19. Bischtube. Cohen: Ann. Wien Naturhist. Mus., 1897, x "> 54- Large, 



flexible plates with included schreibersite. Isolated by HC1. 



20. Penkarring Rock. Fletcher: Min. Mag., 1899, xii, 174. Thin, flexible 



plates. Analysis calculated to 100 after deducting 4.18% schreibersite. 



21. Medwedewa. Berzelius: Pogg. Ann., 1833, xxxiii, 133. Analysis of 



skeleton material left behind after dissolving in HC1. 



22. Beaconsfield. Sjostrdm: Monatsberichte Berlin Akad., 1897, 1041. Tin 



to silver-white, lustrous plates. Iron determined by difference. 



The analyses, as will be observed, show variations of composition 

 from Fe 7 Ni to Fe Ni. While this variation is a wide one it is evident 

 that it is between certain limits, and that it would be incorrect to 

 ascribe too indefinite a composition to tasnite. 



TIMES OF FALL OF METEORITES. 



The following study has' already been published in part by the 

 author.* In the present paper the records are given in full and con- 

 tributions to the subject by other authors are incorporated. 



The times of fall of meteorites may be studied with reference to 

 the year, month, day, and hour. The yearly falls should give evidence 

 as to the frequency of the occurrence and exhibit periods if any occur. 

 The falls by months should show the relation of meteorites to well- 

 established star showers and the portion of the earth's orbit where 

 meteorites are most frequently encountered. The falls by days should 

 exhibit periodicity if any exists and variation in the uniformity of 

 supply. Finally the hours of fall should give the direction of move- 



*Am. Jour. Sci., 1910 (4), 29, 211— 215. 



