210 



THE WONDERS OF GEOLOGY. Lect. III. 



great size are very abundant, either imbedded in the allu- 

 vial sands and gravel, or spread over them. Vast areas, 

 literally covered with boulders, occur in many parts of 

 Europe ; enormous masses of stone lying exposed on the 

 surface of the ground, as bare as when left by the retiring 

 waters, and appearing as — 



" Huge rocks and mounds confus'dly hurl'd, 

 The fragments of an earlier world." 



Many of these boulders are of such magnitude, as more 

 properly to be termed rocks ; being from twenty to forty 

 feet high, and weighing many hundred tons.* 



Connected with the boulders, and beds of drifted gravel 

 and other coarse detritus, is the occurrence of deep grooves, 

 furrows, striae, and scratches, on the upper surface of many 

 rocks, and on the sides of such as flank narrow gorges and 

 valleys, or form the slopes of hills and other inclined planes ; 

 appearances manifestly resulting from the passage of peb- 

 bles, grit, boulders, and angular fragments of hard stone, 

 over exposed surfaces of rocks and strata; in some instances 

 by the action of currents and floods, in others by glaciers 

 and floating ice. In some countries the boulders are not far 

 distant from their parent rocks, and their course and origin 

 may be readily traced ; but throughout a great part of 

 Europe, Asia, and America, these waterworn masses 

 must have been derived from very remote regions ; and 

 they are distributed in such manner, as to show that 

 their transport could not have taken place under the 



* There is a large boulder in the plain near Mount Sinai, which 

 monkish legends identify with the rock of Horeb, whence Moses, by a 

 stroke of his rod, miraculously raised a stream of water for the parching 

 Israelites, It is a block of granite, nearly twenty feet square, which 

 has probably been derived from the neighbouring mountain. — 

 Mr. Greenough's " Critical Examination of the First Principles of 

 Geology :" a work abounding in facts and comments of the highest 

 interest. 



