2 Mr DUNLOP'S Account of Observations made in Scotland 



of many degrees. I can, therefore, have no hesitation in decla- 

 ring it as my opinion, that a ship may be navigated with infinitely 

 more accuracy by one of Professor HANSTEEN'S magnetic charts, 

 than by dead reckoning, and is so perfectly simple, that the 

 merest novice having one of these charts, has only to determine 

 the variation on board his ship, and with the latitude to examine 

 the place on the chart of the intersection of the magnetic curve, 

 which shews at once the position of the ship. 



I trust I may yet see the time when Mr DUNLOP'S observa- 

 tions may be emulated by others, both in this and other coun- 

 tries, which, as they extend the bounds of human knowledge, 

 may be considered a great benefit to man. 



I remain, my dear Sir, yours most truly, 



TH. MAKDOUGALL BRISBANE. 

 JOHN ROBISON, Esq. Secretary Royal Society, &c. 



To Lieut.-Gen. Sir THOMAS MAKDOUGALL BRISBANE, K. C. B. 



SIR, 



I HAVE now the honour of presenting to you the result of 

 my experiments with the magnetic apparatus belonging to the 

 Royal Society of Edinburgh, for the loan of which I feel greatly 

 indebted to the kindness of Dr BREWSTER, and to you in parti- 

 cular, as the expenses of the journey were liberally defrayed by 

 yourself. 



I trust the experiments will be worthy of your acceptance, 

 as they are the most extensive series of any which have yet been 

 made in Britain ; and, in selecting a situation where to make 

 the experiments, I was very careful to avoid the immediate vici- 



