LAGOONS — ALAMO MOCHO. 123 



gradually disappearing the greater the distance from Sackett's wells. In the proximity of the 

 Lagoons the trail was on hard clay, and thence to Alamo Mocho it was mostly sand. This 

 may he looked upon as the most sterile part of the whole desert, on many thousand acres there 

 not heing a hlade of any vegetable growth. In several places a thin pellicle of clay, two to 

 three inches deep, covers the surface, over which are scattered thin and worn specimens of 

 Anodonta, and some small univalve Gasteropoda. 



The southeast wind, rising in the afternoon, and blowing with considerable force, carries 

 quantities of the fine sand with it, rendering it intolerably hot and scorching to the eyes; 

 raising the temperature often to 115° Fah. 



The " Lagoons," which are occasionally filled by overflows of the Colorado river, (distant 52 

 miles,) were, at the period of visit, perfectly dry at Alamo Mocho, so called from the stunted 

 and deformed cotton-wood tree near the springs ;* the water is in the bed of the New river, so 

 called, as being the new course which the Colorado took in its overflow of 1849. The channel 

 bends at this point, and is considerably below the level of its bank upon one side, where yellowish 

 red stratified sand, 35 feet high, abut upon its edge. A new well has been sunk lately by the 

 United States goverment, which is 22 feet deep, and yields an ample supply of water, not less 

 than 500 gallons being removed in 2^ or 3 hours ; which, though it had an evident eflect in 

 lowering the well, yet its place was quickly supplied by a fresh influx of water. The well is 

 defended by a wooden shaft and plank work to keep the sand from caving in, which is carried 

 up 4^ feet above the level of the surface ; a bucket and windlass would be a great boon to this 

 spot, although found difficult to keep them. Two older wells are at a few yards distance along 

 the same line. In one, the timbers have yielded and decayed, and the well is useless ; the other 

 is in good order, but does not yield so large a supply as the new well. 



The whole level plain of the desert at Alamos slopes gently to the south, and in this direction 

 also runs New river bed to meet the Colorado. The line of the bed can be traced by the cotton- 

 woods and mesquite, which are only found growing there. On the level of the desert there is 

 nothing but obione and larrea, the absence of vegetation being thus shown to be due, not to 

 any infertility of the ingredients of the soil, but to the absence of sufficient moisture at the time 

 when vegetable growth requires it. 



There is much more moisture in the air at this part of the desert than further west, at Carrizo. 

 Hills 8 and 10 miles off were indistinct and hazy in outline, neither were the stars so distinctly 

 visible ; but no dew falls at night, the earth not cooling down sufficient to deposit the moisture 

 from the atmosphere, consequently vegetation sufiers almost as much as if the air were wholly 

 deprived of it. Low clouds form in the north, near the horizon, and interchange sheet lightning 

 in distant flashes. f 



The gravel pebbles of the desert are made up of volcanic and silicious material, chiefly the 

 former, of which the reddish porphyry is most abundant ; hyalitic quartz pebbles are common, 

 with hornstone, chalcedony, phrenite, and chabasite, all rounded and polished by attrition so 

 as to be perfectly smooth to the touch ; small fragments are also scattered about there. 



The trail from Alamo Mocho to Cook's well is along the bank of the New river. The surface 

 of the trail between these two waters (22 miles) is more undulating than the former portions of 



""Mocho," Sp. lopped, maimed — by many tbis word has been mistaken as being "mucho" — plentiful — but cotton, 

 woods are not abundant here ; it is too dry a situation for them, while the disfigured tree is not many yards distant from 

 the well. 



t These phenomena occurred during the prevalence of the south wind, which, blowing from the Gulf, may have produced 

 a condition of atmosphere not often found in this region. 



