(56 Mr Arnott's Tmir to the South of France 



manner of the circular wick of an argand lamp. A monochro- 

 matic lamp, made exactly after this method, has lately been ex- 

 hibited, the blue flame being produced from condensed oil-gas. 

 In this instance, the flame was extremely unsteady, having the 

 appearance of the feather-shaped flame produced by a blowpipe ; 

 and it is well known, that an unsteady wavering light is extreme- 

 ly unfavourable to distinct vision. 



Other experiments and observations relating to flame are ne- 

 cessarily delayed for want of room. 



Tour to the South of France and the Pyrenees^ in 1825. By 

 G. A. Walker Arnott, Esq. A. M. F. L. S. & R. S E. 

 &c. In a Letter to Professor Jameson. 



Sir, 



X OU have kindly signified to me a request that I should de- 

 vote a few hours of my time to the giving a short account of 

 my late excursion abroad. This to me is no very easy matter, 

 having kept no regular diary, and but few notes that may amuse 

 you or the readers of your Journal. Such notes, however, as 

 I did keep, aided with Cassini's map of France reduced by 

 Donnet, may enable me to give you at least an outline of my 

 short tour ; and I shall employ the very words of my notes as 

 often as possible. 



It is scarcely necessary to enter upon my journey from London 

 to Paris : that ground is travelled over by so many at the present 

 day, that nothing can be said that almost every one does not know. 

 None, however, but those who have crossed from Dover to Calais 

 can believe in the shortness and pleasure of the sail. In days of 

 yore I do not know how many hours, or even days, were de- 

 voted to this perilous passage ; but, at present, three or four 

 hours is only requisite in those blessed inventions ycleped Steam- 

 boats. The sailors, too, are surely more expert than formerly, 

 or ^olus has more mercy, as we never hear now of a Tom 

 Pipes thrusting his body through the deck to take the com- 

 mand of the vessel, when captain and all have given over every 

 thing for lost. Nor do we feel that any one now thinks of ta- 

 king the precaution (still, however, recommended by the sapient 



