SALTER — A CHRISTMAS LECTURE OX COAL. 125 
hangings in the stndio of the geologist. Who ^11 try copies from 
nature for this purpose ? 
Fig. 7. — Sigillaria elesrans. Fig. 8.— Sigillaria Defrancii. 
Patterns of Ijark Sigiliaria. Pattern of the markings on the Ijark. 
But Sigillaria is not always found lying prostrate. It is very often 
upright, as it grew ; so many instances are known of this that it is 
almost useless to repeat them. A stump, ten feet high, is figured in 
Dr. Mantell's " Wonders."* a book worthy of every young geologist's 
ambition. Others have been noticed by Sir Charles Lyell, and a whole 
forest of short stumps was discovered in 1838, near Chesterfield, dtiring 
the diggings for a railway. There were no less than forty trees — a 
few feet apart — on this one spot. In Durham, at Newcastle, and in the 
South Wales coal-basin, others have been found. Hugh Miller, in 
his interesting book — "First Impressions of England and the Eng- 
Hsh," (p. 233; — has described his visit to the celebrated Wolver- 
hampton coal-forest. Here seventy-three stumps, in thi-ee tiers, 
one over another, are closely packed : and three successive forests 
— on the same spot — seemed to him the best way of accounting for 
it. I think we have a better explanation; but I am not sure of that. 
But, then, these trees have roots to them ; and the discovery of these 
roots has opened up a new chapter in the history of coal. Nay, it 
has deciphered that history ; for till Sir W. Logan found that every 
coal-bed had its underclay full of roots, and till Mr. W. E. Binney, of 
Manchester, traced these roots (which are called Stigmaria, (fig.), 
to their connection with the tree, we never truly knew how coal was 
formed. 
2nd Edition.— By T. Ilupert Jones, Esq., Yice-Sec. Geol. Society, 1858. 
