280 Mr Maclaren's Hemarks on Natural Terraces 



above their base, which may be the remains of one or more 

 ancient sea-bottoms, broken up by strong currents. The ma- 

 terials are invariably sand and water-worn gravel, except at a 

 few spots where the rock protrudes. 



Near Luncarty we meet with what I am disposed to con- 

 sider as remnants of an ancient sea-beach or sea-bottom. 

 They are insulated platforms of sand and washed gravel, from 

 20 to 50 or 100 yards in diameter, flat on the top, and very 

 nearly of the same height. They can scarcely have less than 

 100 feet of elevation above the Tay at Perth. They may be 

 considerably higher. Several of them are near each other, 

 and merely divided by fissures with steep sides, from 10 to 40 

 feet in depth, precisely such as little currents would cut out 

 in a bed of alluvium. See the section below. 



^^^jr^-'-Xr-^^ 



In this figure, aba are three platforms near each other, and 

 of equal height. They are divided and bounded by the fis- 

 sures, 12 3. In some of these fissures, as 1, I was able to 

 judge of the depth from pretty large trees being nearly con- 

 cealed in them. All these elevations, as already stated, are 

 of sand or fine gravel. I saw marks of stratification in some, 

 and have no doubt that they exist in all. 



At Dunkeld, and on the banks of the Tay, far above it, I 

 was delighted to find terraces so distinct and conspicuous that 

 no geologist, who had once turned his attention to the subject, 

 could question their existence. 



On the north bank of the Tay, eastward of Dunkeld, a 

 plateau or terrace extends three-fourths of a mile in length, 

 and of a breadth varying from 50 to 600 yards. It is almost 

 perfectly level, and is backed by lofty precipices of quartzy 

 slate, against which it abuts as sharply as the waters of a lake 

 do against the mountains which confine it. A farm-house or 

 hamlet, called Haughend, stands at its inner corner, and the 

 picturesque villa of Doctor Fisher occupies its western extre- 



