472 Miscellaneous Intelligence. 
approach, I estimated that none of the swarm passed within less 
than three or four miles of us. The insects were evidently trans- 
¥ 
They continued to pass in apparently undiminished number until 
the daylight failed. Meanwhile the stragglers, which had visited 
us in such profusion, disappeared; and the next day single speci- 
mens could with difficulty be found. : 
On the Ist of September the phenomenon was repeated, the in- 
sects returning from the south borne on a wind which moved at 5 
or 6 miles an hour. They were descried at a distance of certainly 
not less than a dozen miles, moving directly upon us; but the wind 
hauled from 8, to 8.E. an hour later and saved us. The change of 
direction was very manifest, and the effect of the change of wind 
could be seen as it successively reached the different parts of the 
long procession. The Sierra, which extends N. and 8. immediately 
west of Cordoba, the foothills rising at the distance of about 
miles, barred their westward progress, and the train passed between 
us and the Sierra for many hours. I was able to fix the height of 
the swarm by sighting against the peaks, and ascertaining on the 
following day the distance at which they had passed. The alti- 
seven miles, possibly less; the whole environed by a penumbra of 
copious stragglers. Yesterday and the day before, the nort wind 
brought them back again for some hours of each day, but to-day 
the wind has returned to the south, and since I began this page 
they have come upon us in full force, literally darkening the sun, 
