200 Doc. No. 75. 



To the Rapides of the Machuca, (the present limits of the "EngHsli 

 claim,) the last, largest, and worst, the river is deep and free from ob- 

 structions. These rapids," says Bulow, who is disposed to represent 

 the capabilities of the river in the most favorable light, are worst of ail; 

 the water is more broken from running over a rocky bed ; stones and rocks 

 project above the surface for a distance of six hundred yards; and great 

 attention is necessary in passing the channel." It may, nevertheless, be 

 passed by small steamers. Prom this point to the San Carlos the river is 

 very fine, the banks high and studded with beautiful trees. The current 

 is regular, but the depth of water variable. Bnlow states the depth at 

 from two to six fathoms. The San Carlos is a large stream, and may be 

 ascended by bungos to the distance of fifteen or twenty miles. 



From the river San Carlos to the Serapique the banks are good, though 

 not so elevated as they are higher up the stream. The current is strong 

 but even, and the depth from four to twenty feet in th.e channel. The 

 Serapique is navigable for canoes to the distance of twenty-five or thirty 

 miles. 



To the divergence of the Colorado river is a distance of thirteen mileSy 

 the banks preserving their elevation to the divergence of the Juanillo^ 

 from which point they become very low. The current is regular, and the 

 depth, according to Bulow, from ten to thirty feet. The Colorado with- 

 draws a large body of water from the river, which, however, continues to 

 preserve very nearly its original width to the port of San Juan. The channel 

 for the remaining distance is studded with low islands, covered generally 

 with gamalote. The depth is very variable, ranging from three to ten or 

 twelve feet; the bottom gravelly. In the dry season bungos can hardly 

 pass with their loads. 



It has been suggested that the channel of the Colorado was cut or en- 

 larged by the Spaniards, under the empire, to prevent the ascent of hostile 

 vessels; but the suggestion is simply absurd. The delta has existed very 

 nearly in its present form and condition, without doubt, for many centu- 

 ries. The loss of water by the Colorado has been calculated at 28,000 

 cubic yards per minute in the dry, and 86,000 in the rainy season. 



I have no hesitation in asserting that the San Juan never can be made 

 navigable for ships of any considerable size. Small steamers, with some 

 improvements in the channel, might be run without much difficulty ; and 

 this is all that can be hoped for from this stream. 



In case it should be determined to open communication for ships across 

 the continent at this point, it would be necessary to cut a canal at the base 

 of the hills parallel to the stream, which might be made to yield;> at the 

 necessary intervals, the requisite supply of water. It is possible that the 

 river might be used from the lake to Del Toro, though even this is not 

 certain. I am convinced that the ground rises not very far back from the 

 river on the north, and that stone and all the materials necessary for the 

 construction of a canal might be obtained without diificulty very nearly on 

 the spot desired. These are things, however, which can only be deter- 

 mined from actual survey. A canal upon the southern bank, for reasons 

 sufficiendy obvious from what has been presented above, is impracticable. 



It has been conjectured by some that formerly the volume of water in 

 the San Juan was much more considerable than it now is. This conjec- 

 ture was doubtless founded on the circumstance of strong defences hav- 

 ing been erected by the Spaniards many years since upon the banks both 



