diversion of showers to the north, along their eastern sides.

During the survey of the boundary line between Mexico and California,
etc., by the commission under Mr. Bartlett, it became necessary to find
some spot where water and grass were abundant, for the head quarters of
the commission. This was found, and _could only be found_, upon the
Mimbres Mountains, at an old abandoned Spanish copper mine, 7,000 or 8,000
feet above the level of the sea, surrounded with peaks of still greater
height. These elevated ranges were within influential distance of the
counter-trade, and here snow fell in the winter, from the extra-tropical
belt, and rain, in showers, in summer, at the period of the most northerly
extension of the tropical belt; when fifteen miles off, in the valley, it
was unbroken drought. Mr. Bartlett thus describes it in his Personal
Narrative:

"We reached this district on the 2d of May. Vegetation was then
forward, though there had been no rain. But it must be remembered
that during the winter there is snow, and hence a good deal of
moisture in the earth when the spring opens. The months of May and
June were moderately warm. On the third of July the first rain fell.
It then came in torrents, accompanied by hail, and lasted three or
four hours. Many of our adobe houses were deluged with water, and the
mountain-sides exhibited cataracts in every direction. The Arroyo,
which passes through the village, and which furnishes barely water
enough for our party and the animals, became so much swollen as to
render it difficult to cross; and, by the time it had received the
numerous mountain torrents, which fall into it within a mile from our
camp, it became impassable for wagons, or even mules. The dry gullies
became rapid streams, five or six feet deep, and sometimes fifty feet
or more across. On this day, a party, in coming to the copper mines,
from the plain below, _where there had been no rain_, found
themselves suddenly in a region overflowing with water, so that
their progress was arrested, and they were obliged to wait until the
flood had subsided. After this we had occasional showers, during the
months of July and August."

The location of this mountain station is near the thirty-third degree of
north latitude, while the northern limit of the equatorial belt, nowhere,
except upon the mountain ranges and table-lan