OF LOCHABER. 63 



tually somewhat lower, than the surface of the moss lying be- 

 tween it and Loch Spey. In Dr MacCulloch's Tabular View 

 of Elevations, he makes the highest parallel of Glen Roy to be 

 1266 feet, and Loch Spey 1203 feet, above the German Sea, 

 and, consequently, the shelf to be 63 feet above the loch. 

 Although my own observations have led me to form so very 

 different an opinion about this matter, and although this opi- 

 nion has been since borne out by the highly respectable testi- 

 mony of Mr Macdonald of Inch, yet I should have almost 

 hesitated in supposing, that so very accurate and philosophical 

 an observer as Dr MacCulloch could have been mistaken, did 

 he not himself seem to imply a doubt in his own mind of some 

 error having arisen in the measurement of this very elevation. 

 This he expresses in a note which I hope Dr MacCulloch's 

 consideration will forgive me for quoting, as I doubt not his 

 liberality will pardon me for thus expressing my difference of 

 opinion with regard to the state of a fact, of which I feel con- 

 vinced. The words of this note are as follows : 



" Whatever doubt we may have respecting the general va- 

 ** lue of the method by which the elevation of the upper line 

 " of Glen Roy was ascertained, I must here remark, that this 

 44 principal measurement receives confirmation, to a certain 

 44 extent at least, by comparison with the height of that land 

 " which is the common division of the Truim and the Garry. 

 " This point has been found, by levelling, to be 1460 feet, and 

 44 it appears probable, from comparing the course of the for- 

 44 mer river and that of the Spey to their common junction, 

 44 that the source of the Spey cannot be materially different in 

 " elevation, a circumstance confirmed by the barometric ob- 

 44 servations. The other measures in the Table scarcely ad- 

 44 mit of any material errors." — Geological Transactions, 

 Vol. iv. Part ii. p. 327. 



The 



