4. Agua Zarca.--Wood, water, and grass.

23-1/4. Rancho de las Calabasas.--Wood, water, and grass.

13. Tubac.--Silver mines at this place.

Total distance from Guaymas to Tubac, 295 miles.

NOTE.--During the months of July, August, and September, water will be
found at almost any part of the road from La Casita to Hermosillo.
There is no lack of wood or grass on any part of the road from Guaymas
to the frontier. The only difficulty in encamping at almost any point
upon the road is that of obtaining water in the dry season, _i.e._,
from February to the first of July. The remarks for each place apply
to the most unfavorable seasons.

APPENDIX.

A. _Portable Boat._

A boat has been invented by Colonel R. C. Buchanan, of the army, which
has been used in several expeditions in Oregon and in Washington
Territory, and has been highly commended by several experienced
officers who have had the opportunity of giving its merits a practical
service test.

It consists of an exceedingly light framework of thin and narrow
boards, in lengths suitable for packing, connected by hinges, the
different sections folding into so small a compass as to be
conveniently carried upon mules. The frame is covered with a sheet of
stout cotton canvas, or duck, secured to the gunwales with a cord
running diagonally back and forth through eyelet-holes in the upper
edge.

When first placed in the water the boat leaks a little, but the canvas
soon swells so as to make it sufficiently tight for all practical
purposes. The great advantage to be derived from the use of this boat
is, that it is so compact and portable as to be admirably adapted to
the requirements of campaigning in a country where the streams are
liable to rise above a fording stage, and where the allowance of
transportation is small.

It may be put together or taken apart and packed in a very few minutes,
and one mule suffices to transport a boat, with all its appurtenances,
capable of sustaining ten men.

Should the canvas become torn, it is easily repaired by putting on a
patch, and it does not rot or crack like India-rubber or gutta-percha;
moreover, it is not affected by changes of climate or temperature.

B. _Winter Traveling._

In traveling through deep snow, horses will be found much better than
mules, as the latter soon become discouraged, lie down, and refuse to
put forth the least exertion, while the former will work as long as
their strength hold