“364 Geological Observations 
to its confluence with the Tay, a distance of near thirty miles, as 
the numerous channels by which it has run may be traced with 
tolerable accuracy. 
It appears almost certain, that Lochearn at one time had ex- 
tended to more than double its present magnitude, having oc- 
eupied the whole of the flat from its south-eastern extremity to 
Ochtertyre, covering the great plain on which the village of 
Comrie, the remains of the Roman camp of Dalginross, the Vie- 
toria of Ptolemy, and many farm-houses now stand*. This 
epinion is strengthened and rendered satisfactory by an examina- 
tion of the surrounding country, or what originally marked the 
borders of the lake, where the soil and banks formed by the 
water are visible, and still retain their first appearance, although 
for ages submitted to the operations of agriculture. The soil over 
all this flat is also of a decisive character, being composed of 
water, gravel, and alluvion, as almost all the stones that have 
been dug up are round or elliptical, the certain efieets of water ; 
and this is particularly the case in the neighbourhood of Ochter - 
tyre, along the road from Crieff to Comrie. On the south side 
of the valley, near the House of Struan, there is a large concre- 
tion of breccia, the composition of which is sand, and stones that 
have undergone attrition by the action of water, and have been 
consolidated by the admixture of metallic oxide. This species 
ef rock is not commonly to be met with in the interior of the. 
kingdom, and in no situation but where considerable bodies of 
water either now are, or have formerly been. On the western 
shores of Scotland it is frequently seen; but we are not ac- 
qiainted with its appearance in masses of great magnitude at a 
distance from the coast, nor in situations of very lofty elevation. 
The effiux of Lochearn, in its then extensive form, seems to 
have been different from the course which the river at present 
follows in leaving the plain of Dalginross, and appears to have 
passed from Ochtertyre, whose lakes are the remains of the an- 
cient eastern boundary, along the hollow at the manse of Moni- 
vaird, near to which it was joined by the water of Turret. At 
the present day, the old and perhaps original bed of the river 
Earn can plainly be traced along the west side of the town of 
Crieff, where it still intersects two of the streets, sweeping, in a 
circular direction, the base of the hill on which that town is built, 
and passing eastward, held its course upwards of 90 feet higher 
than the present river. Pursuing that direction, it appears to 
have made several windings until it reached Abereairney, whence 
* Tt has been supposed, by many learned antiquaries, that on this spa- 
cious plain was fought the celebrated battle of the Grampians, betwixt the 
€eledonian and Roman armies; and, certainly, the names of many places 
an the neighbourhood go far to sanction such a belief. 
1 
