4 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



durated clay ; in burning it gives off the characteristic odor of 

 imperfect coal ; the powder is brown, 3 feet, 3 inches to 3 feet, 6 

 inches. This is one of the few localities in Britain where coal is 

 present in workable thickness, but the coal is inferior and no longer 

 of even local importance. Miller'^ has given some notes concerning 

 the Oolite conglomerate of Eigg, one of the Hebrides. The Scuir 

 of Eigg is described as a mass of igneous rock resting on a pile 

 foundation, composed of pine stems, laid crosswise. These stems 

 of Pinites eiggensis are transported material ; they are so numerous 

 near Helmsdale that the people collect them and burn them into 

 lime. The tree was as abundant on the mainland of Scotland as 

 the Scotch fir is at present. It was of slow growth but attained 

 gigantic size. Witham's study of the structure proved it very 

 different from that of the Carboniferous conifers. The wood 

 abounds in turpentine vessels or lacunae of varying size, which are 

 well defined, the minutest detail of structure being distinct. Occa- 

 sionally Miller found a thin streak of brilliant lignite, resembling 

 that of Brora, but in every case it was only the bark of a tree. 



The Lower Oolite in Lincolnshire, according to Morris,^ has 

 soils of vegetation with well-defined underclays. In one section, 

 bituminous clay, 18 inches thick, rests on "gray clay with vertical 

 stems and roots descending from the overlying bed." Another sec- 

 tion shows the bituminous band only 6 inches thick with 7 feet of 

 underclays containing vertical stems. At Dane's Hill the root-bed 

 is only 9 inches, but at Aunby Cutting, he saw two bituminous clays, 

 of which the upper contains lignite and impure coal. Each has its 

 root-bed below. 



The Inferior Oolite, at base of the Lower Oolite, has some coal 

 in Yorkshire. Phillips^ recognized two groups of sandstones and 

 shales along the coast. The lower consists of white to yellow sand- 

 stones and shales, with irregular seams of bad coal ; the plants are 

 cycads and ferns but equisetiform remains are in the upper layers, 

 standing vertically as if in place of growth. A thin irregular seam 



<> H. Miller, "The Cruise of the Betsy," Boston, 1862, pp. 51-55, 71. 



''J. Morris, "On Some Sections in the Oolitic District of Lincolnshire," 

 Quart. Jour. Geol. Soc, Vol. 9, 1853, pp. 326-331. 



8 J. Phillips, " Geology of Yorkshire," 2d ed., London, 1835, Part I., pp. 

 8-10, 65, 66, 173, 174. 



