some Points on the West Coast of Scotland. 305 



4. August 11. Longitude bj chronometer, 



11. 



... 19 



... 19. 



Mean longitude in time, 



in degrees, • 



The observations from which these results have been ob- 

 tained were not so numerous as I could have wished, because 

 part of my time was employed in other pursuits ; but if com- 

 pared with many of our books and charts, they Avill be found, 

 I believe, more accurate. In fact, all the coast, from about 

 the Cloch Light to the Mull of Galloway, appears, by my own 

 observations, combined with those of others, to be placed too 

 far eastward by several miles. For example, the position of 

 Ayr Light is given by different authors as follows : — 



5. The latitude is given — 



By Mackay's Navigation, 1804 and 1809, at . 66° 25' 0" N. 

 ... Lynn's Nautical Tables, 1825, ... 25 



... Norie's Navigation, 1828, ... 25 



1835, ... 28 30 



While I found my station in 1837, ... 28 53 



nearly the same as last, though the light appears to be really a 

 few seconds to the north of my position. 



C. Again, the longitude by 



Mackay in 1804, ..... 4° 26' 0" W. 



Lynn in 1825, ..... 26 



Norie in 1828, ..... 26 



1835, ..... 37 



The preceding, from my observations, is . . 4 36 21 W. 



nearly agreeing with the last of Norie's, though the light may 

 indeed be about half a minute to the westward of my position. 

 I think it would have been credited by few, that the geogra- 

 phical position of the county town of Ayr had been till within 

 these few years so badly determined, or at least so erroneously 

 given in our best books and charts, on which it was supposed 

 implicit confidence might have been placed. * 



" Dr Mackay states, in the explanation of his Table of Latitudes and Lon- 

 gitudes, that " the positions of many of those places on the west coast of Scot- 

 land were communicated to him by Mr Lamont of Greenock." 1 have been 



