and summer floods of the Mississippi, when the waters, &c., adjacent to the gulf shall have been brought to such a degree of temperature as is necessary to produce fermentation and putrefaction. At this and all higher degrees of temperature the process of decomposition is carried on more or less rapidly, attended by the production of gasses, which, in combination with the soft mud overlaid by the crust or indurated covering before mentioned, gives to the underlying mass a specific gravity materially less than that of the water, deposits, &c., lying above the crust. Hence the crust must yield at its weaker or thinner points, an uprising of the same ensues, and those hitherto anomalous productions called "mud lumps" ensue.

The uprising of the indurated covering continues until the coverings crack open at their highest points, and the gasses gradually escape through the fissures, carrying with them small streams of water, exceedingly turbid, and of saline and bitter taste. The gasses thus escaping are invariably inflammable, like the bubbles arising from the bottoms of fens or stagnant pools.

The numerous mud lumps that have come under my personal observation have invariably presented a covering of stiff adhesive clay, rent and divided by fissures on almost every portion of their surface. They assume all possible forms; those of the smaller dimensions being somewhat conical in their form, while those of the larger sizes present themselves in the shapes of ridges, some of them nearly straight, while others are curved and recurved, presenting very irregular and ragged outlines. Some of them present orifices like craters, through which the gasses and salt springs escape, while others present no other openings but prolonged fissures, through which their imprisoned air, mud, and water are set at liberty.

It is true of almost every mud lump, however minute or spacious, and whether above or below the surface, that a pole or stake driven through their indurated covering, enters into a soft yielding mud, and may readily be thrust downwards to a great depth with very little resistance.

Mud lumps of the character above described are nowhere to be met with except in the vicinity of the inner margin of the tidal bar, of which last, as also of the swamps in its rear, they constitute not only the substratum, but the entire superstructure of mud, &c., erected thereon.

S. H. LONG,

Lieutenant Colonel Topographical Engineers.

No. 11.

Colonel Long to Colonel Abert.

LOUISVILLE, June 20, 1857.

SIR: Sundry letters have been received from Captain Wm. Johnson in relation to the operations of Messrs. Craig & Rightor at the Southwest Pass, and to the changes producedt hereby in the channels

across the tidal bar during the month of May last. Hence it appears that early in that month a strong gale from the southeast prevailed for several days, and contributed to the rupture of the upper portion of the line of piles, through a distance of about 800 feet; also, that at the end of the month the rupture had been repaired, and that the contractors continued sanguine in the belief that their enterprise would be crowned with ultimate success.

At the date last mentioned, (May 31,) the contractors had succeeded in repairing all defects in the line of piles, and in extending the same to an aggregate length of about 3,000 feet. The work thus extended remained stable and unaffected by storms at that date; no violent gales having occurred since the protracted gale above noticed.

From the observations of Captain Johnson, it also appears that no perceptible changes have been produced in the bed of the Pass, except a slightly accelerated current along the upper side of the line of piles, the depths of the soundings across the Pass, as also in the channels across the tidal bar remaining unchanged.

Captain Johnson has been directed to continue his observations in the manner prescribed in my instructions of the 18th of April last, a copy of which has been sent to the bureau, and to keep me apprised of the results produced by the operations of the contractors, while I hold myself in readiness to revisit the work whenever it shall appear that the contractors shall have got it ready for final inspection.

In addition to the documentary information received from and through the bureau on the subject of the passes, I have succeeded in obtaining the manuscript reports of Captain Talcott, and his associates, Messrs. Lidell & Meade, on the same subject, and have caused the same to be entered among the records appertaining to the improvement of the mouths of the Mississippi.

S. H. LONG,

Lieutenant Colonel Topographical Engineers.

No. 12.

Colonel Long to Colonel Abert.

LOUISVILLE, July 30, 1857.

SIR: Agreeably to a report of Captain Johnson, received on the 28th instant, it appears that the operations of Messrs. Craig & Rightor at the Southwest Pass, during the month of June last, have been attended with serious discouragements and doubtful success. The line of piles has been extended southwestwardly only about 300 feet during the month, while the line, through a distance of about 100 feet of its northeastern portion, has been disrupted and driven from its moorings. Hence the extent of the line still remaining on the 30th June is only about 3,200 feet, while as yet it appears that nothing had been done towards the formation of a counter line of piles on the northwesterly side of the Pass.

Boisterous weather had prevailed during most of the month, by which not only the progress of the work had been much retarded, but some four or five of the signals for the triangulations had been carried

away.

With respect to the improvement of the channel, no favorable. changes are yet perceptible, and doubts are still entertained as to the efficiency of the mode of improvement adopted by the contractors under the sanction of the War Department. S. H. LONG,

Lieutenant Colonel Topographical Engineers.

No. 13.

Colonel Long to Colonel Abert.

LOUISVILLE, August 20, 1857.

SIR: Agreeably to a report of Captain Johnson, dated on the 31st ultimo and this day received, it appears that the work of Messrs. Craig & Rightor had advanced rather tardily during the month of July last, and that the benefits resulting from it continued doubtful at that date.

The line of piles had been prolonged southwestwardly towards the tidal bar, with a deflection of about five degrees to the right, through a distance of about 1,100 feet, making the entire length formed at the close of the month about 4,300 feet.

From the soundings on the lines of the triangulations it does not appear that either the depth or width of the main navigable channels has been increased in consequence of the work that has been done under the contract, except in so far as relates to a perceptible divergence of the outflows of the water across the tidal bar from the left to the right or northward, which appears to have been occasioned by the line of piles.

The weather appears to have been less boisterous and more favorable for the prosecution of the work during the month of July than it had been during the preceding month.

S. H. LONG.

No. 14.

M. P. Breckinridge to Col. Long.

LOUISVILLE, September 1, 1857.

SIR: In compliance with your order of August 12th, enclosing a copy of the queries from the topographical bureau of April 24, 1856, and other papers, requiring of me a report upon western commerce and the steamboat disasters of the western rivers for the fiscal year

ending on the 30th of June last, I submit the following, premising that, in consequence of the short time allowed me, it is necessarily incomplete in many respects. A report embracing detailed information in regard to the commerce of the western rivers, canals, and railroads, would be a work of great time and labor, and would give one person constant employment in collecting the requisite material. In the course of my inquiries, in addition to the information obtained at this point, I visited Cincinnati and St. Louis for the purpose of gathering such statistics as could be had in furtherance of the object in view. The commerce of these three cities, though a comparatively small item in the whole, and detailed in a very imperfect manner in this paper, will convey some idea of the extent of western trade.

From the published proceedings of the fifth annual meeting of the board of "supervising inspectors" of steam vessels, I extract the following information in regard to the number of steamboats inspected, and their tonnage, for the year ending October 1, 1856:

The subjoined table, showing the amount of receipts of a few of the principal articles of trade at Louisville, is compiled from an annual commercial report in the Louisville Courier. The amounts would have been much larger if any accurate accounts of the receipts by wagon had been kept.

By river
By railroad.
By wagon

Bbls. flour. Sacks wh't. Sacks corn. Bbls. whiskey. Pieces bag- Bags coffee.

ging.

Total....

I am indebted to Mr. W. N. Haldeman, collector of the port, for the following table of the monthly duties collected at the custom-house, and for the number of steamboats registered and their tonnage.

Vol. ii-22

Duties received during the year ending June 30, 1857.

The total number of steam-vessels registered at the port of Louisville for the same year is 85; number of tons burden 26,594.65; showing an average capacity to each boat of 301.11 tons. A moderate average for the cost of these boats would be $25,000 each, giving the sum of $2,125,000 of capital invested in steamboats. There are also numerous barges and keel-boats used in carrying freights up and down the river; and besides these many flat-boats descend the Ohio to Louisville annually, laden with coal, lumber, and other products of the number of these and the value of their cargoes I am unable to give a very correct estimate, but they are probably not less than two hundred, with an everage value of $500.

For the subjoined statement of duties collected at the Cincinnati custom-house for the fiscal year I am indebted to Mr. R. T. Reilly, deputy collector of the port.

The annexed statements in regard to the commerce, &c., of the Ohio river at Cincinnati, and the imports and exports by railroads, canals, and river, were kindly furnished by Mr. Wm. Smith, superintendent of the Merchants' Exchange.

Number, tonnage, and cost of steam and other vessels at Cincinnati.