THE FORMATION OF COAL. 85 



THE FOKMATION OF COAL. 



IN the course of a pedestrian excursion made in the 

 summer of 1855 I came upon the Aachensee, one of the 

 lakes of North Tyrol, rarely visited by tourists. It is 

 situated about 30 miles N.E. of Innispruck, and fills the 

 basin of a deep valley, the upper slopes of which are steep 

 and richly wooded. The water of this lake is remarkably 

 transparent and colorless. With one exception, that of the 

 Fountain of Cyane a deep pool forming the source of the 

 little Syracusan river it is the most transparent body of 

 water I remember to have seen. This transparency re- 

 vealed a very remarkable sub-aqueous landscape. The 

 bottom of the lake is strewn with branches and trunks 

 of trees, which in some parts are in almost forest-like 

 profusion. As I was alone in a rather solitary region, 

 and carrying only a satchel of luggage, my only means 

 of further exploration were those afforded by swimming 

 and diving. Being an expert in these, and the July sum- 

 mer day very calm and hot, I remained a long time in the 

 water, and, by swimming very carefully to avoid ripples, 

 was able to survey a considerable area of the interesting 

 scene below. 



The fact which struck me the most forcibly, and at first 

 appeared surprising, was the upright position of many of 

 the large trunks, which are of various lengths some alto- 

 gether stripped of branches, others with only a few of the 

 larger branches remaining. The roots of all these are more 

 or less buried, and they present the appearance of having 

 grown where they stand. Other trunks were leaning at 

 various angles and partly buried, some trunks and many 

 branches lying down. 



On diving I found the bottom to consist of a loamy pow 

 der of gray color, speckled with black particles of vegetable 

 matter thin scaly fragments of bark and leaves. I brought 

 up several twigs and small branches, and with considera- 

 ble difficulty, after a succession of immersions, succeeded 

 in raising a branch about as thick as my arm and about 

 eight feet long, above three-fourths of which was buried, 



