418 Analysis of Vul IX, Part L of the Transactimis 
the mountains of Lochaber, particularly those which bound the 
valleys of Glen Gluoy, Glen Roy and Glen Spean. 
The highest of these roads or shelves is observed on each side of 
Glen Gluoy, and in Glen Roy there are three other shelves, the 
uppermost of which is about 12 feet below that of Glen Gluoy* 
The second is about 80 feet lower than the first, and the third 
about 200 feet below the second. The two upper roads of 
Glen Roy are confined to that valley, but the lowest extends into 
Glen Spean and round the upper e^ctremity of Loch Laggan. 
All these different shelves have corresponding ranges in the 
opposite sides of the valley on the same level, and by means of 
careful levelling, they were found to maintain the horizontality 
characterizing the surface of water throughout all the various 
windings of their linear extent. And whenever an isolated hill 
happens to rise from the bottom of the valley above the level 
of any shelf, a delineation runs round the little hill at a level 
corresponding to that of the shelf on the mountains which 
bound the glen. 
The formation of these roads has been ascribed by tradition 
to the Kings of Scotland, when the royal residence was in the 
Castle of Inveriochy, and also to the Eingalians, in consequence 
of several of the hills being named after the heroes of Fingal* 
Sir Thomas Lauder, however, considers these opinions as un- 
tenable, and attributes the formation of the parallel roads to the 
action of the waters of a lake which has stood at different heights 
corresponding with that of the shelves, and which has subse- 
quently burst through its confining barrier, in consequence of 
some great convulsion which formed at the same time the great 
glen of Scotland through which the Caledonian Canal is now 
carried, 
It is very remarkable, that the Parallel Roads should have 
been so seldom visited even by our own countrymen. If they 
are works of art, they must possess a high interest in the esti- 
mation of the historian and the antiquary ; and if they are the 
result of natural operations, an opinion which we think demon- 
strable, they afford an ocular proof of a great local convulsion 
which must have preceded the records of authentic history. 
This paper was written before the author had seen the very 
learned and ingenious Essay of Dr MacCulloch, On the 
