Brownsville, situated on the American side of the river fifty miles from its mouth by the course of the river, is only twenty-two miles distant by the road. It contains about three thousand inhabitants. The houses are mostly of wood and well built. The town has sprung up since the Mexican war, and owes its prosperity chiefly to the contraband trade with Mexico.

Opposite Brownsville is the ancient town of Matamoras, with a population about the same in number as Brownsville.

Below Brownsville, and adjoining it, is the military post, with old Fort Brown at the farthest extremity of the public grounds. In the middle of the parade ground, unmarked by any monument, lie the remains of the gallant officer who fell in defence of the fort which now bears his name. The height of Fort Brown above the sea is, by barometrical measurement, fifty feet. The mean temperature for the years beginning 1850, and ending 1855, was 73° Fahrenheit; the mean quantity of rain in the same years was annually 33.65 inches. These quantities are taken from the Army Meteorological Register, and are used in preference to my own, as they cover a much longer space of time. They would seem to indicate an abundance of rain for all the purposes of agriculture, and we should be at a loss to understand the arid character of the country on both sides of the river, were it not that the tables give us the solution; we there find that more than one-half the rain falls in the autumn, which is followed by a winter during which the thermometer frequently falls below the freezing-point. One-fourth the whole quantity of rain falls in a single month, and it very often happens that no rain whatever falls in the months of May, June, and July. Consequently, throughout the whole valley of the Rio Bravo and its tributaries, we seldom see corn growing except in the bottoms, subject to over

flow, or upon lands which are below the water-level and can be irrigated by artificial channels. Somewhat of this barrenness is due undoubtedly to the excess of lime and saline matter with which the soil is charged.

As we ascend above Brownsville, lands within the water-level become more frequent and extended, and at many places cultivated fields form a prominent feature in the landscape. Up as high as Reynosa, the belt of alluvial soil subject to the influence of the moisture from the river is very considerable in width, and in addition to corn, the sugar-cane has been planted with success. The foliage on this portion of the river indicates a richer soil, and the trees assume very much the dimensions of those on the alluvial bottoms of the Mississippi.

It is within this region, embracing a river coast of one hundred miles, that the sugar-cane can be cultivated to advantage; and in situations sheltered from the northers, I have no doubt oranges and lemons could be raised with facility.

Property, however, is very insecure all along the boundary, and unless extradition laws with Mexico are passed, this fertile tract will never have its capacities developed.

The boundary between the United States and Mexico is here only an imaginary line running down the centre of the river, and an offence can be committed on either side with impunity. A few minutes served to place the offender over the line, when the jealousies of the law on either side step in to protect him; and where national prejudices are involved, the criminal is not unfrequently extolled for his exploits.

It was in the summer of 1853 that this portion of the boundary was surveyed, and a revolution headed by Caravajal was in its last throes. This chief had retired to the American side of the river, and was occupied in making occasional forays into Mexico, aided by some American volunteers, mostly composed of young men, whose tastes for civil pursuits had been destroyed by the Mexican war. These efforts were attended with no other effect than that of irritating the peaceable inhabitants on both sides, and were of great inconvenience to us in the prosecution of the survey. Attempts were made several times to stop the parties under my command engaged in the survey of the river, and on one occasion nothing but the forbearance of the officer in command prevented his party from firing upon a detachment of Mexican cavalry which threatened to charge them. In the absence of the Mexican commissioner, I was at length compelled to make a direct appeal to General Cruz, then in command on the Mexican side, who promptly gave orders along the line which had the effect to lessen, in some degree, the interruptions to which the surveying parties were exposed.

We were scarcely more in favor on the American side of the line; for some months previously the United States troops had interfered with a strong hand to break up the enlistment of men and the concentration of fillibustering forces on our side of the river. Although most of the hired men employed by me were disbanded fillibusteros, the parties escorted by a detachment of United States soldiers were usually mistaken for military scouts in search of the violators of the law, who at that time composed the majority of persons on the frontier.

Some idea of the reckless character of the persons then infesting that frontier may be formed from the following circumstance, the truth of which is vouched for by several respectable eyewitnesses. My own camp was but a short distance from the place where the scene occurred:

One mild summer's evening several gentlemen, among them a retired officer of the fillibusteros, were enjoying the delicious twilight of that climate on the bank of the river opposite a point where was usually posted a picket-guard, detached from a Mexican military station four miles distant. The guard of ten men were seen to approach the jacal, dismount, tie their

horses, and stretch themselves on their blankets, some to sleep, others to smoke, but none particularly to watch.

The conversation of the first-named party was rather of a jocose character, directed at the expense of the young American fillibuster who had joined in the Caravajal revolution, which had just been ended with such signal advantage to the regular Mexican troops. A little nettled, probably, at what had passed, he offered a wager of one hundred dollars that he would cross in a boat and take the guard, single-handed. His wager not being accepted, he offered to bet "drinks for the party." Some person, not dreaming he was in earnest, indiscreetly took the bet.

The absence of the fillibuster was scarcely noticed, and the conversation about other subjects had continued for nearly an hour, when it was interrupted by the sharp reports of a revolver, and a yell which reverberated from shore to shore, giving the impression of many voices; these were quickly followed by the rolling fire of a platoon of musketry, and then all was silent. "Could that be S-?" asked one. "Impossible!" was the reply. "It would be just like him," said a third. Shortly after a boat containing two or three men was seen to dart across the rapid current from the shadow of the high bluff on the American side. As it approached the opposite side, its occupants, not wishing to violate the usages of the guard, called out in Spanish they were friends, going over to see what was the matter. "Matter? Hell!" answered a voice in English, "Come here and help me to drive these mustangs in the river. They found the guard dispersed, and S with one arm shattered by a musket-ball; with the other he was trying to lead all the ten horses to the river-shore.

Reynosa is a small Mexican town of about 1,500 inhabitants, opposite an American settlement called Edinburgh, with one or two substantial warehouses. The last-named town, like all the others on the American side, except Loredo, has been built since the war, and owes its existence chiefly to the contraband trade with Mexico. Reynosa is built on a low cretaceous ridge, and it is here the first rocks above the surface are seen; yet none appear on the immediate banks of the river until we reach Las Cuevas, some distance above, where we find a stratum of cretaceous sandstone 10 or 15 feet thick. At the last named point, and thence up the river, there is also a marked diminution in the quantity of bottom-land susceptible of cultivation, and vegetation changes its character, becoming more dwarfed and spinose. The uplands on either side impinge close upon the river, and the vegetation is principally mezquite and cactus. On the Texas side, as we recede from the river, the chapparal gives place to the open prairie, covered with luxuriant grass. This character of the river lands extends with little variation up to Ringgold Barracks.

This military post consists of a few comfortless frame houses, situated half a mile below Rio Grande city. Opposite, and four miles from the Rio Bravo, is the town of Camargo, of about one hundred inhabitants. It is situated on the San Juan river, the first unfailing tributary to the Rio Bravo from the Mexican side. It is one of a series of rivers which rise in the so-called Sierra Madre, and go to supply the Rio Bravo in summer, the season of tropical rains, when that river most requires replenishing, as then the supply of water from the melting of the snows at its northern sources is nearly exhausted.

Ringgold Barracks was one of the points selected for the close determination of latitude and longitude to check the lineal surveys, and a point from which excursions could be made with facility, to determine secondary points by reflecting instruments and by the transmission of chronometers.