ON THE ORIGIN AND FORMATION OF COAL. 



of their apparent paths show them to have been chiefly directed from this radiant 

 point. Greg's shower at R. A. 43°-}-26 , Oct. 18 — Nov. 14, is no doubt iden- 

 tical with this, but its importance has only lately been recognized. This may be 

 the same as an October shower at R. A. 46°-j-27°, (25 meteors); and there is a 

 display of long pathed meteors from the latter point, on the mornings of the early 

 part of August. 



to. R. A. 8i°-f-23°, (53 meteors,) Nov. 22 — Dec. 21. Maximum, Dec. 

 6. Taurids II. observed in 1876. The meteors are bright and slow moving. 

 They were reobserved by Sawyer, in 1877 and 1878. In September and Octo- 

 ber, this same radiant at Beta-Zeta Tauri is clearly indicated as a shower center 

 of some importance, R. A. 8o°-)-22 , (47 meteors,) and both Zezioli and Tup- 

 man traced it; the former at R. A. 84°-j-2i°, Oct. 12-31; and the latter at R. 

 A. 7'8 +2 3 °, Sept. 8-10. 



Bristol, England, Feb. 14, 1879. — Science Observer. 



GEOLOGY. 



ON THE ORIGIN AND FORMATION OF COAL. 



BY PROF. E. L. BERTHOUD, COLORADO SCHOOL OF MINES. 



The term, "coal," was first used in a restricted sense, meaning glowing 

 embers of wood, then charcoal itself. To-day we mean by "coal" any mineral 

 fuel that will ignite and burn with flame and incandescent heat, whose component 

 parts are carbon, hydrogen, oxygen and nitrogen mixed with small amounts of 

 earthly or mineral impurities; but in all the amount of carbon generally exceeds 

 all other constituents of the mineral coal. 



At first, in geological works forty or fifty years since, the "true coals" as 

 they were called then, were supposed to be found only in the carboniferors for- 

 mation — all coals found either below or above these "coal measures " were looked 

 upon as either adventitious and accidental deposits, or, when found in formations 

 above the "carboniferous," considered as "lignites." These arbitrary divisions 

 have been found untenable, and to-day we know that true coal not only exists 

 in formations older than the Carboniferous strata but also in the Jurassic, Per- 

 mian, Cretaceous, and lastly in the Tertiary formations of such extent and magni- 

 tude as to exceed vastly in amount all the coal known to exist in all the strata 

 beneath it. 



Not proposing, in this lecture, to go into a chemical crit'eism on the subject 

 of all the varieties of coal, I will simply state, that with many others I do not 

 believe in the classification or appellation of our Colorado coal as a "lignite coal." 



