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The following letter from Mr. N. Patten, collector at Galveston, gives a good idea of the amount of busiuess transacted at this place duriug 1871 and 1872:

CUSTOM-HOUSE, GALVESTON, TEX.,

Collector's Office, February 3, 1873. Sir: I take pleasure in rendering the information you solicit in your communicatioll of the 30th ultimo, relative to the commerce of this port.

In answer to your interrogatories I submit the following: 1st. Number of entrances of steam, 1871

277 Number of entrances of steam, 1872

252 2d. Tonnage of same, 1871....

298, 116 Tonnage of same, 1872.

395, 755 3d. Clearances-steam, 1871 Clearances-steam, 1872

252 4th. Tonnage of saine, 1871.

303, 173 Tonnage of same, 1872.

276, 414 5th. Entrances-sail, 1871

339 Entrances- sail, 1872

330 6th. Tonnage of same, 1971

135, 235 Tonnage of same, 1872.

115,330 7th. Clearances-sail, 1871. Clearances-sail, 1872.

315 8th. Tonnage of same, 1871.

132, 820 Tonnage of same, 1872.

119, 457 9th. Total value of imports dutiable, 1871

$1,5-6,094 Total value of imports dutiable, 1872

1, 302, 535 10th. Total value of imports free, 1871

314 Total value of imports free, 1872

311, 221 11th. Total value of exports, 1871

16, 157,504 Total value of exports, 1872

12, 056, 570 12th. Duties collected on imports, 1871

693, 521 74 12th. Duties collected on imports, 1872

6-2, 934 24 I remain, sir, very respectfully,

NATHAX PATTEX,

Collector. H. M. Adays,

Lieutenant of Engineers, T. S. A., Galveston, Tex.

I bave been assisted in the survey of Galveston Harbor by Mr. H. C. Ripley. His report forms a part of the record of our work, and is forwarded herewith. Very respectfully, your obedient servant,

H. M. ADAMS,

Lieutenant of Engineers, C. S. d. C. W. HOWELL,

Captain of Engineers, l'. S. A.

H. C. Ripley, assistant engineer, reports to Lieutenant Adams, iu regard to the conduct of the survey, as follows:

GALVESTON, Tex., June 23, 1873. DEAR SIR: I have the honor to make the following report on the survey of Galveston Harbor and entrance, Texas.

The field work was commenced October 7, 1872, and conducted on the same general plan as that adopted for the United States Coast Survey.

The triangulations were made with a transit manufactured by W. & S. E. Gurley, Troy, N. Y., and since it was the cause of some delay and dissatisfaction, a brief statement of some of its peculiarities may not appear out of place.

The telescope has not sufticient power to discover an object the size of a man at a distance of more than about three miles, in the clearest weather, and consequently it was exceedingly difficult to see my stations, or to locate buoys and beacons, some of which were at a distance of four and five miles. This was a source of considerabile delay, but the great source of error is in the graduation of the horizontal limb. Each angle was repeated from three to five times, and although the instrument is gradnated to read to single minutes, a ditference as great as two minutes las been observed in the same angle read from different parts of the limb). However, the country being open and level, I have been able to check the work in so many ways that the meau result for the position of any station does not differ from the extreme limit, in cases of greatest discrepancy, by more than three feet, and consequently, in so small a survey, will

not affect the accuracy of the chart. But this is sufficient to show that in a survey of any extent such an instrument would be entirely inadeqnate for the purpose.

Between the stations located by triangulation, transit lines were run to compute the topograp!ıy. In this case the instrument being invariably set up on the reverse of the last reading taken, the error of graduation did not show itself and the result attained was remarkably good; the greatest error in azimuth in joining any two stations was three minutes, in a distance of two and one-half miles. The principal source of delay in the triangulation was due to foggy weather, but most of the time was utilized taking topography. The hydrography was commenced as soon as the stations were built.

For this purpose there was at my disposal the tug “ Hall," which was used for outside soundings, and a small four-oared boat for inside and shallow soundings. I was able to utilize much of the windy weather by sounding outside when the wind blew off shore and inside when it blew from the Gulf. The only drawback to this admirable arrangement was the exceeding difficulty in preventing the "Hall” from getting aground. She draws seven and one-half feet of water, and since at low-tide in many places on the bar there is less than this depth of water, and there have been many changes since the last coast-survey chart was made, it was impossible to keep her from grounding occasionally if she ventured from the regular channel. This being true in still water, the least swell increased the depth of safety and a large swell made it dangerous to cross the bar, even in one of the channels. It was in this way that she broke her stern-post, November 30, passing out the “cylinder channel” in nine and one-half feet of water and scarcely any wind, and was thus disabled for further use uutil the soundings were finished. The " Hall ” being withdrawn for repairs, the “Rattler,” a sloop of five tons, drawing about three feet of water, was chartered, with which the outside work was completed. This answered the purpose very well; but a larger one, and drawing no more water, would have been preferred. However, we were able, with a moderate breeze off shore, to do more work with her than with the “Hall," and at much less expense.

The soundings were taken with a pole, to the depth of ten feet, and given iu feet and tenths. At greater depths they were taken with a line, with ten-pound lead, and given in feet and half-feet.

The character of the bottom was given and recorded at every change in its nature. The locations were made from the boat by means of two sextants, with objects on shore, the position of the boat being located every two to five minutes. The soundings were taken as often as the leadsman could conveniently heave the lead, averaging about four soundings per minute, in twelve feet of water.

The difficulty of locating was the great source of embarrassment in the entire survey, and was occasioned by the almost constant prevalence of fog. The tripod stations were entirely useless, except in the clearest weather, or when near them; and altbongh all prominent objects, snch as light-houses, beacons, buoys, wrecks, church-spires, &c., were located and used, yet the condition of the atmosphere was such, much of the time, that it was difficult at a distance of four or five miles to distinguish one object from another, even if it conld be seen at all.

When the wind was blowing, especially from the north or west, it was generally clear, but as soon as it became calm enough for sounding, a fog was most certain to

Almost the only exception to this was immediately following a fierce “ norther," when one or, perhaps, two days would be clear and fair.

The soundings were commenced November 4, 1872, and continued during favorable weather, until completed, January 24, 1873.

The following is the statement of the time actually employed taking them :

rise.

In November
In December
In January

Hours. Minutes. 68

45 66

49 46

36

Total

182

10

At seven bours per day, an average day's work, this gives 26 days.

The whole number of days is 81, giving a ratio of 1 to 31 as the time favorable for this kind of work. The whole number of soudings taken is 30,000; but with the scale adopted for the chart only about one-fourth of this number, or 7,5500, were plotted. Toe hydrographic area embraced in the survey is about 42 square miles. This gives an average of 714 soundings per square mile, avd 161 square miles of hydrography completed per day. A tide-gauge was kept from the beginning of the survey and the reading recorded every half bour, day and night. It was located at the eastern end of the city, as being the most available point convenient of access. It would have been desirable to have had one on the outer bar, but this was impracticable in the absence of a self-registering gange. As the ne:rest approach to the outer bar, a second

gauge was kept at Fort Point for a period of twenty days, by means of wbich a ratio was established between it and the one in the city. By means of this ratio, the outside soundings were reduced, and the almost universal agreement in them, where lines of soundings crossed each other, proves the result not unsatisfactory.

CURRENTS.

The current observations were commenced as soon as the sonndings were completed For this purpose a keg, weighted with lead to make it sink, and suspended with a small cord to a tin tloat just sufficient to buoy it up, was arranged. The cord could be made of any desirable length, and, since the float was small compared with the keg, the velocity of the float would be very approximately that of the current at the depth determined by the length of the cord. To measure the velocity, a log-line was attached to the float, and the time occupied in running out any known distance was noted. The direction of the float was taken with a mariner's compass; at the same time the bearing of one or more known objects was taken to test the accuracy of the compass, the boat being anchored and its position located. Observations were taken at the surface, mid-depth, and bottom, and repeated three or more times. For these observations such days and stages of the tide were selected as should give the greatest velocities.

CONCLUSIONS.

The swiftest currents occur when the moon's declination is large, and during the last quarter of the ebb and the first quarter of Hood tide. They are also influenced by wind.

The tide begins to flood in Bolivar Channel some time before it ceases to ebb in Galveston Channel. It also flows along the flats and margins of Galveston Channel before it has ceased ebbing in the center. At the outer end of the break water at Fort Point when the flood first sets in, it flows directly across the channel to the west, and, meeting the ebb-tide, foris a partial eddy, which is doubtless the cause of the middle ground or shoal place on the inner bar.

At certain stages of the tide the water flows between Pelican Island and Pelican Spit in the direction indicated by the arrow, the velocity varying greatly at different times; but it has never been observed to run in the contrary direction. It is possible that this contributes to the formation south of Pelican Spit.

The tide at the gange begins to rise generally from one to three bours before flood sets in.

The littoral current does not seem to be affected by the tide, but runs in one direction for days at a time, and then will change and take the opposite direction or cease to run altogether, depending apparently upon the direction and force of the wind. It, however, has its effect on the tide, influencing the direction at which it crosses the outer bar. Thus, when there is no littoral current and the tide flood, it crosses the bar normal, or yearly so, to the direction of the bar itself; but when the littoral current is running to the northeast the direction of the tide will be deflected from the normal to the north; when it is running to the southwest it will be deflected to the south, and in a degree corresponding to the velocity of the littoral current and the force of the tide. The same is true at ebb-tide, but perhaps not to so great an extent.

To show the uncertainty of this littoral current, it is worthy of note that three observations, on different days, were taken beyond the intluence of the tide, when it was impossible to discover any current whatever. At other times it bas a velocity of onehalf mile per hour, and perhaps greater. This, however, is the greatest velocity observed.

TIIE CILART.

The plotting was continued during unfavorable weather for field or hydrographic work until they were completed, and then it was continued with slight interruptions until finished. The principal stations and some of the more prominent objects used for locating soundings were plotted by co-ordinates. The secondary stations, used in topog. raphy and ininor objects, were plotted by intersection. The shore-iine is that of mean low-tide, as near as could be produced by means of the tide-giunge and the location of high-water of the day and the water's edge at the time.

Many of the current observations were not plotted, siuce only those slowing an appreciabile velocity were considered of any value. Very respectfully, your obedient servant,

H. C. RIPLEY,

Assistant Engineer. Lieut. H. M. ADAMS,

Corps of Engineers, U. S. A.

From the facts established by this survey, and by previous surveys officially reported to the Chief of Engineers, the following may be gathered and presented as important in considering plans of improvement:

PLAN OF HARBOR ENTRANCE AND BAYS.

The Gulf coast, from Calcasieu River past Galveston to Aransas Pass, has a trend nearly northeast and south west. Galveston entrance is a little east of the center of this stretch. Entering Galveston Harbor from the Gulf we first meet with what is known as the outer bar, stretching in a semicircle from Bolivar Peninsula on the east to Galveston Island on the west, across the entrance to Galveston Bay, and affording over its crest only a depth of 12 feet of water, a depth but slightly exceeded or decreased within the time covered by reliable record. Passing this bar we enter the wide, deep tide-bore known as Bolivar Channel, affording a depth of 40 feet, separating Bolivar Peninsula from Galveston Island, and, after passing both, branching out into the shallow water of Galveston Bay, which latter, with its east and west bays, affords a water area of 455.12 square miles, daily served by the Gulf tides through Bolivar Channel.

Opposite the head of Bolivar Peninsula a branch of Bolivar Channel, leaving at right angles to the latter, runs along the curving inner face of Galveston Island, forms Galveston Harbor, and loses its depth in the shoal water toward West Bay.

Obstructing this branch, and opposite the head of Galveston Island, is what is known as the inner bar. Separating this branch from the other branches of Bolivar Channel is a large middle ground, of which Pelican Spit and Pelican Island are the only portions out of water.

The fresh-water streams of any size discharging into the bay are the Trinity and San Jacinto. These debouch at the head of the main bay, thirty statute miles from the outer bar. Their mouths are obstructed by bars formed of the grosser deposits brought down by their currents, and about midway of Galveston Bay the lighter deposit is arrested by Redfish Bar, extending entirely across the bay. There is no indication of river deposit having reached the outer bar.

CHARACTER OF FORMATION.

The npper stratum of Galveston Island, Bolivar Peninsula, Pelican Spit and Island, and of the bars, is of the fine rounded sand peculiar to the islands forming the cordon littoral of the Gulf coast. It has all the characteristics of a quicksand, is easily moved, when dry, by the wind; the littoral current mores it back and forth along the coast; waves and tidal currents, where it is exposed to their action on the bars, shift it with every change in direction of wind and velocity of current, making frequent changes in the shape of the bars and the channels across them. Vessels grounding on it strike as on a rock; vessels wrecked by the action of the currents induced by their presence gradually sink beneath the surface.

It affords the least desirable of all foundations on which an engineer may be obliged to build.

Its depth increases from the bay outward, with a dip to the eastward, as is best shown by the sections and diagram submitted.

The strata beneath are of sand, shells, and clay in varying proportions, gaining in consistency with depth, the lowest stratuun resting on

the stiff blue clay underlying the wbole Gulf coast formation west of the Florida Reefs.

This clay stratum outcrops at Sabine Pass, east of Galveston, and at the mouth of the Brazos River, west of Galveston. From Galveston its dip appears to be to the eastward.

Without borings along the coast, we may venture the supposition that Bolivar Channel is about on a synclinal axis of this stable forunation.

The land about the entrance is low and flat.

CHANGES IN SHORE LINES, BARS, AND CHANNELS.

Comparing the charts submitted herewith (of this survey and of 1850 and 1851) and those of 1867 and 1841, sent to the Chief of Engineers with the report of Gen. M. D. McAlester, made in 1868, marked and continued changes in shore-lines, bars, shoals, and channels will be observed. The following are the most important noted :

SHORE-LINES.

The northeast point of Galveston Island (Fort Point) since 1841 has steadily moved to the westward, since 1851 retaining essentially the sameoutline; up to 1851 it had moved 700 yards; from that to 1867, 400 yards; from that to the time in 1870 when the movement was checked by the jetty construction then started, it moved 100 yards.

It is now 1,200 yards west of its position of 1841.

On the Gulf side of Galvestou Island the movement has tapered to nil at a point opposite Galveston City, and on the harbor side has been confined to the immediate neighborhood of the Point.

This movement was followed by a corresponding advance of Bolivar Point, opposite.

In 1811 Pelican Spit was a shoal to the west of Fort Point. As the movement of Fort Point progressed, this became shoaler and moved westward in proportion to the movement of the Point.

It is not known at what time it appeared above water, but it was some time before 1851. From 1851 to 1867 it moved directly west about 500 yards, retaining its shape and height.

In 1872 it was about 200 yards farther west, bad retained its shape at the northern end and greatly widened at the southern. It has moved faster, it will be observed, than Fort Point, thus increasing the distance between the two.

Pelican Island has not materially changed.

CHANGE IN BARS,

The inner bar has been created since 1811, at which time Galveston Harbor and Bolivar Channel were connected by a channel 30 feet deep.

The commencement of the bar was first noted in 1813, from which time until 1867 it shoaled irregularly but persistently to about nine feet, and lengthened in proportion to the movement of Fort Point.

In 1872 works of improvement before referred to had increased the depth to 12 feet.

The outer bar was moved slightly gulfward, and only suffered temporary changes in the depth of water over its crest, which depth is now, as it was in 1841, about 12 feet.

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