2G2 ANNUAL OF SCIENTIFIC DISCOVERT. 



ish threads and films of talc in the quartz ; d, in crystals of sul- 

 phide of iron mechanically mixed with the pyrites ; e. attached to 

 the walls of decomposed and removed crystals of pyrites ; f, in 

 the ochre resultant of such decomposition ; g, in thin, film-like 

 scales on the face of fissure walls ; h, in masses cementing- frag- 

 ments of gangue rock together. 



4. In the foot and hanging walls of veins, the " cacasjo" of the 

 country. 



There are two systems of veins, one running north-east and 

 south-west, the other east and west. In both of these there is a 

 variation of from 10 to 30 degrees. Which of these systems is the 

 oldest we have not yet determined. — Scientific American. 



PETROLEUM IN THE CAUCASUS. 



According to Prof. Von Koschkull, of Tiflis, Russia, the petro- 

 leum region surrounds the whole range of the great Caucasus in 

 the tertiary rocks, in their three subdivisions. Especial attention 

 has been given to petroleum springs in the north and on the shores 

 of the Caspian. The Persians have used it for many ages for 

 various purposes. The wells are 20,000 in number, and from 2 to 

 100 feet deep. The oil flows into the pits with water, and is daily 

 skimmed oft\ Some of this oil is very light in color and gravity ; 

 some is brown, and is finally reduced to asphaltum formations. 

 In 1865, the American method of boring for oil was introduced 

 into the Caucasus. A well, at the depth of 40 feet, gave a flow 

 of 22,000 kilogrammes of oil daily. The temperature of the oil is 

 3° R. One jet was 60 feet in height. The oil has been purified 

 and used to great advantage. 



COAL IN NEBRASKA. BY. F. V. HAYDEN. 



During the geological survey last season, the greatest interest 

 was felt in this question by the people, from the fact that nearly 

 all the State is a treeless prairie. Even a bed of coal, of moder- 

 ate thickness, at a reasonable depth, would be of inestimable 

 value, and the solution of this problem seemed to be the most im- 

 portant one of the survey. It is now known that all the carbonif- 

 erous rocks of Nebraska belong to the upper coal-measures, and 

 that these rocks occupy but a small area in the south-eastern por- 

 tion. 



It is now pretty well proved that, in the upper coal-measures of 

 the West, there are no workable beds of coal, and that, while 

 thin seams occur in many places, they never attain a thickness of 

 more than 2 or 2i feet. 



Near Nebraska City, on the Missouri, an outcropping, about 8 

 inches thick, has attracted some attention. 



This seam has been wrought bj^ drifting a distance of 300 yards 

 or more, and several thousand bushels of pretty good coal have 

 been taken from it. At Brownsville, there is a seam of coal 



