HISTORY OF THE SOCIETY. 



503 



mense advantages which those parts of the Empire are already 

 deriving from the admirable trigonometrical operations by 

 which their physical geography has been defined, your Memo- 

 rialists beg leave humbly, and most respectfully, to urge upon 

 your Lordships' attention the very defective state of the best ex- 

 isting Maps and Charts of Scotland, and to suggest to your 

 Lordships the propriety of directing the resumption of the Tri- 

 angulation, and completion of the Trigonometrical Survey, of 

 Scotland, which has been so long and unaccountably suspended, 

 after it had been auspiciously commenced. 



" The errors in Arrowsmith's Map of Scotland, which has 

 the reputation of being the best we possess, are so numerous and 

 important as to render the construction of a Geological Map of 

 the country, on which dependence can be placed, an impracti- 

 cable undertaking ; while its erroneous positions of our Coasts 

 and Islands present the most formidable obstacles to navigation. 

 The form and position of headlands, and even of considerable 

 islands, in this map, and in our best charts, are erroneously 

 given ; and sometimes dangerous rocks and whole islands are 

 totally omitted. For example, your Memorialists beg leave to 

 call your Lordships' attention to the following facts. The dis- 

 tant rocks of the Stack and the Skerry, off the northern coast of 

 Sutherlandshire, as well as the Island of St Kilda, are totally 

 omitted in Arrowsmith's Map, while the important Islands of 

 Barra and Rona are misplaced, both in latitude and longitude. 

 In some charts the large Island of Arran is laid down as six miles 

 from Bute ; in others as nine miles, and in a third as twelve miles 

 distant from that island. Pladda Island Light, in charts, is 

 placed as 16' N. of Ailsa Craig ; whereas its true distance is only 

 10' 20". These last are serious errors at the entrance of so im- 

 portant a river as the Clyde. 



" Some years ago Dr MacCulloch was employed, at the public 

 expense, to make a Geological Survey of Scotland, a circum- 

 stance utterly unknown to any public body in Scotland, until 



