10 
EXCESSIVE BKILLIANCY OF THE SKIES. 
is easily accounted for by the excessive temperature of these plains, and the consequent effect of 
ascending currents and general rarefaction. 
After several days of rain and a consequent decrease of temperature, these clouds descended 
and enveloped the summits of the mountains. During the period referred to the sky was never 
entirely overcast, and the rain came in terrific thunder showers, as many as eight or ten being 
observable in different parts of the sky, but moving parallel from a little south of east to the 
opposite point of the horizon. 
We have said that a southwest wind prevailed all along the Grila as far as the Pimas villages. 
This breeze generally died away at sundown and a temporary lull prevailed until the moon rose, 
when almost immediately a comparatively cool and gentle breeze set in from the point of rising 
and continued more or less during the night. This phenomenon was observed for several days, 
from two days’ march below the Maricopas wells to Tucson. 
The excessive brilliancy of the skies was frequently remarked in these regions, even near the 
horizon. On the evening of the 3d of July, as a part of the train had fairly entered upon that 
long and dreaded jornada between the Grila and Tucson, we were riding in advance reflecting 
on the dreary march before us, with no little misgiving as to its issue : the head of Scorpio had 
passed the meridian, and the planet Jupiter, toward whose cheering light our pathway lead, 
was in the southeast; for some moments we had perceived a phantom-like presence on our left, 
which we were at a loss to determine or account for, when, on closer inspection, a scarcely appre¬ 
ciable shadow of ourself and mule was perceptible, following along the ground. Perceiving it 
to be constant, and proceeding from no passing meteor or terrestrial object, we took out a note¬ 
book, and holding a pencil before a blank leaf detected a well-defined shadow proceeding from 
the luminous portion of the galaxy near the southern horizon, and the brilliant stars of the 
beautiful constellations Scorpio and Sagittarius; no shadow was apparent from Jupiter, though 
shining with unwonted splendor.* 
Numerous meteors were of almost nightly occurrence, both in California and across the conti¬ 
nent, their general direction being southwesterly. 
* Since penning the above paragraph I have discovered in my reading several allusions to this phenomenon of brilliancy, by 
travellers in eastern climes. In an Appendix to Burton’s Pilgrimage to El Medinah and Meccah is an account of it, given by 
Banks, the translator of Giovanni Finati’s Narrative, who was one of the three Christians who have succeeded in penetrating to 
that sanctum sanctorum of the Mohammedan. In Morris’ Tour in the East the following passage occurs in a description of the 
passage of the desert between Cairo and Suez : “There was no moon in the sky, but the blue roof above us was fretted with 
multitudes of dazzling stars, that cast a faint illumination upon the desert.” There is a striking resemblance between the Arabian 
deserts, as described by intelligent travellers, and the Colorado and Sonora deserts, in geology, topography, vegetation, and to a 
remarkable degree in the customs of the respective populations ; to fully present these resemblances would be to swell this paper 
beyond its legitimate limits. 
