375 
THE PAEALLEL EOADS OF GLEN EOY. 
Br Professor TYNDALL, D.C.L., LL.D., F.E.S., &c. 
[PLATE CXLI.] 
T HE first published allusion to the Parallel Eoads of Glen 
Eoy occurs in the appendix to the third volume of Pennant’s 
64 Tour in Scotland,” a work published in 1776. 44 In the face 
of these hills,” says this writer, 44 both sides of the glen, there 
are three roads at small distances from each other and directly 
opposite on each side. These roads have been measured in the 
complete parts of them, and found to be 26 paces of a man 5 
feet 10 inches high. The two highest are pretty near each 
other, about 50 yards, and the lowest double that distance from 
the nearest to it. They are carried along the sides of the glen 
with the utmost regularity, nearly as exact as drawn with a line 
of rule and compass.” 
The correct heights of the three roads of Glen Eoy are 
respectively 1,150, 1,070, and 860 above the sea. Hence a 
vertical distance of 80 feet separates the two highest, while the 
lowest road is 210 feet below the middle one. 
These 44 roads ” are usually shelves or terraces formed in the 
yielding drift which here covers the slopes of the mountains. 
They are all sensibly horizontal, and therefore parallel. Pen- 
nant accepted as reasonable the explanation of them given by 
the country people, who thought ‘ 4 they were designed for the 
chase, and that the terraces were made after the spots were 
cleared in lines from wood, in order to tempt the animals into 
the open paths after they were rouzed in order that they might 
come within reach of the bowmen who might conceal themselves 
in the woods above and below.” 
In these attempts of 44 the country people” we have an 
illustration of that impulse to which all scientific knowledge is 
due — the desire to know the causes of things ; and it is a 
matter of surprise that in the case of the parallel roads, with 
their weird appearance challenging inquiry, this impulse did 
