114 Correspondence of J. Nicklés. 
In 1806, he left for Spain, where he continued under the direction 
of M. Biot, the measure of the meridian of France, which had been 
interrupted by the death of Mecham. On the demand of the National 
Convention which established oe Decimal system, Delambre and Me- 
chain undertook the measurement of an are of the meridian between 
elevated peaks of Catalonia, our observer had to contend in turn with 
the wind, the cold, and hunger, and also with peiccnooh the chief of 
whom ended by becoming the Protector of our young savants. 
year after their departure for Spain, MM. Biot ater Arago had 
nearly eanalee the measurements as regards Spain. The former 
then returned to Paris, and Arago went on to Majorca to continue his 
operations. But the war was on the point of breaking out between 
ovements of the yo Frenchmen who remained at work about the 
summit of Canstes: rendered him an object of suspicion to the Major- 
but at the moment of entering the Gulf of Lyons, the vessel was cap- 
tured by a Spanish corsair and conducted to Rosas; Arago and his, 
of Palamos. At last, through the reclamation of the Dey of Algiers, 
to whom the vessel belonged, Arago and his associates were returned 
to Algiers. Buta revolution had ‘there taken place, and the Dey had 
just been decapitated; the new Dey was unwilling to let Arago go 
away, whom he supposed to be possessed Mi gro and-under the 
direction of the Danish Consul, and Ara as consequently thrown 
into slavery. Finally, after a series st visiieitaiies of various kinds, 
he succeeded again in quitting Algie d on the 2nd of July, 1809, 
> an 
he entered the lazaretto of Marseilles, with all his instruments which 
he had succeeded in preserving, 
France had believed him dead. The first letter which arrived an 
him at the Lazaretto was one from Humboidt, who knew him only fro 
his misfortunes, and from that time a friendship commenced pada n 
these two great men which continued to the end. On the 17th of 
the September following, Arago entered the Institute: be was then 23 
years old. Already he bad made with Biot an 
fore had not been oor he had determined the relation between 
12, the Bureau des Longitudes charged him with ‘the delivery 
of a course of lectures on Astronomy at the Observatory, which was 
