ARRIVAL AT CORUNNA. 93 
through the Dardanelles, while it enlarged the ba- 
sin of the Mediterranean, overwhelmed the southern 
part of Europe. The high central plain just de- 
scribed would, it may be presumed, resist the ef- 
fects of the inundation until the escape of the waters 
by the strait formed between the Pillars of Hercules 
had gradually lowered the level of the Mediterra- 
nean, and thereby once more laid bare Upper Egypt 
on the one hand, and on the other, the fertile val- 
leys of Tarragon, Valentia, and Murcia. 
From Astorga to Corunna the mountains gra- 
dually rise, the secondary strata disappear by de- 
grees, and the transition rocks which succeed an- 
nounce the proximity of primitive formations. Large 
mountains of graywacke and graywacke-slate pre- 
sent themselves. In the vicinity of the latter town 
are granitic summits which extend to Cape Orte- 
gal, and which might seem, with those of Brittany 
and Cornwall, to have once formed a chain of 
mountains that has been broken up and submersed. 
This rock is characterized by large and beautiful 
erystals of felspar, and contains tin-ore, which is 
worked with much labour and little profit by the 
Galicians. 
On arriving at Corunna, they found the port 
blockaded by the English, for the purpose of inter- 
rupting the communication between the mother- 
country and the American colonies. The principal 
secretary of state had recommended them to Don 
Rafael Clavigo, recently appointed director-general 
of the maritime posts, who neglected nothing that 
could render their residence agreeable, and advis- 
ed them to embark on board the corvette Pizarro 
bound for Havannah and Mexico. Instructions were 
