ISIS,] 



Mxtent of the Counties of Scotland, 



Article V. 



Extent of the Counties of ScotJand ; ascertained ly Mr. Jardine 

 and Sir George Stewart Mackenzie. Communicated by Sir 

 George Mackenzie. 



In order to ascertain, with as much precision as possible, the 

 superficies of Scotland, and of the different couniits into which 

 it is divided, a copy of Anowsmith's map was selected, the 

 paper of which was nearly of uniform thickness. A portion of 

 each sheet, equal to 5000 English square miles, measured from 

 the scale of the map, was carefully weighed ; the balance used 

 in this, and the subsequent operations, being sensible to the 

 one-hundredth part of a grain, when loaded with 21 bs. in each 

 scale. Each county was then accurately separated by means of 

 a sharp-pointed knife, and its weight compared with that of the 

 portion of the sheet to which it belonged. In those counties 

 which contained a considerable portion oi fresh water lakes, the 

 lakes also were separated and compared in a similar manner; and 

 from these data the surfaces of the land and water of each 

 county were deduced. The map of Scotland constructed by 

 Arrowsmith is undoubtedly the best that has hitherto been 

 published. it does contain a few errors in the' positions 

 of places, and a few in the courses of rivers ; but none have yet 

 been discovered that can affect the present calculation in any 

 material degree. Indeed, if Arrowsmith took greater pains to 

 render one part of his map more accurate than another, it was 

 in ascertaining the boundaries of counties ; and in doing this he 

 was liberally assisted by the Parliamentary Commissioners for 

 Highland Roads and Bridges. On the whole, the following 

 table may be regarded as the nearest approximation to the truth 

 hitherto attempted. The method employed seems to have been 

 first made use of by Dr. Long, of Cambridge, in the year 1742, 

 to ascertain the proportion of the land to the water, on the sur- 

 face of the earth. 



It must be observed, that from a recent comparison, made 

 with great accuracy, of the Scotch standard ell, and the Eng- 

 lish standard yard, it appears that the Scotch chain should be, 

 at the temperature of 60° of Fahrenheit, 74 1234 English feet, 

 instead of 74*4, the length of the chain in common use. In the 

 calculations by which the table has been constructed, the 

 correct length was used, which makes a difference of above 

 11,000 Scotch acres to be added to what the sum would have 

 been^ had the common measure been employed. 



