IMPROVEMENT OF CHINCOTEAGUE INLET, VIRGINIA.

51ST CONGRESS, 1st Session

HOUSE OF REPRESENTATIVES

Ex. Doc. No. 207.

IMPROVEMENT OF CHINCOTEAGUE INLET, VIRGINIA.

LETTER FROM THE SECRETARY OF WAR, TRANSMITTING Report and recommendations concerning improvement of Chincoteague Inlet, Virginia, by a breakwater.

FEBRUARY 14, 1890. -- Referred to the Committee on Rivers and Harbors.

WAR DEPARTMENT,
Washington City,

February 10, 1890.

The Secretary of War has the honor to transmit to the House of Representatives, in compliance with the requirements of the river and harbor act of August 11, 1888, a letter from the Chief of Engineers, together with the report of Maj. W. F. Smith, U. S. Army, retired, United States agent, upon the survey of Chincoteague Inlet, Virginia, and also a copy of his report upon the preliminary examination of the same.

REDFIELD PROCTOR,
Secretary of War.The SPEAKER OF THE HOUSE OF REPRESENTATIVES.

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OFFICE OF THE CHIEF OF ENGINEERS,
UNITED STATES ARMY,
Washington, D.C., February 6, 1890.

SIR: I have the honor to submit herewith a copy of the report dated February 4, 1890, upon the survey of Chincoteague Inlet, Virginia, for the purposes of a breakwater, made under the direction of W. F. Smith, United States Agent, Major of Engineers, U.S. Army, retired, to comply with the requirements of the river and harbor act of August 11, 1888.

A copy of the report upon the preliminary examination of the locality, dated October 30, 1888, is also herewith.

The project submitted provides for the construction of a breakwater -- 12,000 feet long, a jetty from Wollop's Beach 10,250 feet long, and a jetty at Fishing Point 4,900 feet long, at a total estimated cost of $3,782,688.

It is not understood that Major Smith recommends that the work be undertaken at present.

Very respectfully, your obedient servant,

THOS. LINCOLN CASEY, Brig. Gen., Chief of Engineers

HON. REDFIELD PROCTOR,
Secretary of War.

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PRELIMINARY EXAMINATION OF CHINCOTEAGUE INLET, VIRGINIA,
FOR PURPOSES OF A BREAKWATER,

UNTIED STATES ENGINEER OFFICE,
Wilmington, Del., October, 30, 1888.

GENERAL: In compliance with the requirement of section 14 of the river and harbor act of August 11, 1888, and the instructions contained in the letter from the office of the Chief of Engineers of September 29, 1888, I have the honor to submit the following report upon the preliminary examination of Chincoteague Inlet, for purposes of a breakwater, Virginia.

Chincoteague Inlet, is situated in Accomac County, eastern shore of Virginia, about 60 miles south of the Delaware breakwater harbor. The roadstead east of the mouth of the inlet known as Tom's Cove is frequented as a harbor of refuge by coasting vessels sailing eastward and caught by northeasterly gales. It is, however, open to southerly and southwesterly, winds, and is therefore dangerous. It is the only refuge between the capes of Virginia and those of the Delaware, and vessels that fear being caught on a lee shore by a sudden change of winds avoid it by running back to Hampton Roads.

The improvement would afford a secure harbor in stress of weather, and prevent much loss of time and danger to vessels in the coasting trade; it is, therefore, in my opinion, worthy of improvement and a survey is recommended.

The least amount required to make a survey with report, and estimate of improvement is $1,000.

A breakwater constructed as desired, about 1 mile in length, would cost about $1,700,000.

A copy of the report of Mr. D.C. Hudson, who assisted in making the examination, is inclosed herewith,

Very respectfully, your obedient servant,

The CHIEF OF ENGINEERS, U.S.A.

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REPORT OF MR. D.C. HUDSON.

UNITED STATES ENGINEER OFFICE, Wilmington, Del., October 30, 1888

SIR: In compliance with your order of October 10, 1888, I proceeded at once to Chincoteague Island, Virginia, and on the following day passed out of Chincoteague Inlet in a small steamer and ran across Assateague anchorage, commonly known in that section as Tom's Cove, to within a short distance of Fishing Point.

Assateague anchorage is situated nearly due east of the entrance to Chincoteague Inlet and is about half way between the mouths of the Delaware and Chesapeake bays. In its present condition it is a fine natural roadstead for coasting vessels during dangerous northeast winds that frequently prevail on this coast. On the north and west complete protection is given by the shores of Chincoteague and Assateague islands. On the south, however, there is nothing to break the fury of the waves, and when the winds above referred to suddenly veer to that quarter, great distress falls upon the storm-beaten traders that have taken refuge within this otherwise well-protected anchorage.

The distance from Chincoteague Inlet bar to Fishing Point is about 2 1/2 miles. This point is said by persons living in its vicinity to be rapidly extending southward. If this be true the ship shoals are gradually being covered by the beach sands, thereby enlarging the roadstead and extending the protection against easterly storms.

The construction of a breakwater from some point east of Chincoteague Inlet across the cove to the small shoal south of Fishing Point would, if properly located and constructed, form a well-protected harbor more than a mile square, with a depth of water varying from 18 to 25 feet, with good holding bottom, and at all times accessible without crossing a bar.

A harbor at this point would be of inestimable value to the coasting trade. Northbound sailing vessels are often confronted with such strong head winds, when only a few miles south of the Delaware Breakwater, that they are compelled to turn and seek a place of safety southward. Assateague anchorage is a tempting present relief, but may bring sorrow in case of a sudden change of wind to the south. Chincoteague, Wachapreague, and the two Machipongo Inlets are eagerly watched, but if the weather is too thick to find a buoy, or if a buoy is found, a bar white with breakers often deters them from thus seeking a passage to the coveted and safe waters beyond, all the inlets are passed, a stormy cape that often robs them of a good part of their deck-load is crossed, and at last they are safely moored in Hampton Roads, having lost 100 miles of vantage ground held twelve or fifteen hours before.

Sailors in the coasting trade say that this is not an unusual occurrence. Scores of vessels are caught between the two bays by every northeast gale, and something of the security to life and properly that would result from such an intermediate place of safety can readily be seen. At the custom-house on Chincoteague Island I learned that more than one hundred vessels at one time had been known to take refuge in Assateague anchorage, risking a sudden change of wind rather than encounter the perils of a trip further south. In my opinion this anchorage is now about as safe as the Delaware Breakwater harbor, and, with the improvement suggested, would form a complete harbor, easy of access, deeper, and of more than twice the safe capacity of the Delaware Breakwater, and without an Henlopen to cross.

I learned also that one hundred and three vessels, varying from 5 to 65 tons, trade in and out of Chincoteague Inlet, together with about two hundred smaller vessels, under 5 tons, and decked. From twelve to fifteen vessels trade in pine wood, each making about twelve trips per year. The smaller boats carry oysters to Philadelphia and points on the New Jersey coast. They also bring plants front the Chesapeake Bay, at, the regular seasons, to be placed in the numerous oyster beds in Chincoteague, Johnson's, and Parker's bays. Quite an extensive business in sea--fishing is carried on.

On the morning of the day this examination was made twenty-five or thirty vessels of the smaller fishing vessels had passed out of the inlet and were found lying in Assateague anchorage awaiting the developments of the weather. An increasing northeast storm held them at bay and drove them within the inlet. By noon a regular gale had set in and we too were obliged to seek a place of safety and defer our trip up the bay until the following day. Vessels trailing out of this inlet find the anchorage a very convenient place to wait for daylight or fogs to clear up on their return trips, to enable them to find the way over the bar.

It is roughly estimated that a breakwater 1 mile long would cost about $1,664,663. Before any details can be given an accurate survey must he made, and it is estimated that it would cost $1,000.

Very respectfully, your obedient servant,

D.C. HUDSON.

Gen. WM. F. SMITH,
United States Agent.

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SURVEY OF CHINCOTEAGUE INLET, VIRGINIA, FOR PURPOSES OF A BREAKWATER.

UNITED STATES ENGINEER OFFICE, Wilmington, Del., February 4, 1890.

GENERAL: In compliance with the instructions contained in the letter of April 6, 1889, from the office of the Chief of Engineers and the requirements of the river and harbor act of August 11, 1888, I have the honor to submit the following report upon the survey of Chincoteague Inlet, Virginia, for purposes of a breakwater, made under my direction during the month of August, 1889.

There can be no doubt about the benefit arising to commerce from the establishment of a harbor of refuge midway between the capes of Virginia and those of the Delaware. The limit to which expense for such a harbor should go is another question.

The jetty proposed from the mainland south of the Chincoteague Inlet would doubtless be of great service in improving that inlet in accordance with the scheme for an inland water way from Chincoteague bay to Delaware Bay, near Lewes, Del.

The project and estimates taken from the report of Mr. A. Stierle, the assistant engineer who made the survey, are for a breakwater 12,000 feet long, a jetty on Wallop's Beach 10,250 feet long, and a jetty at Fishing Point 4,900 feet long, at a total estimated cost of $3,782,688.

A copy of the report of the assistant engineer is herewith inclosed.

A tracing of the map of the survey is now being made and will be forwarded as soon as completed.

Very respectfully, your obedient servant,

WM. F. SMITH,
United States Agent.

THE CHIEF OF ENGINEERS, U.S.A.

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REPORT OF MR. A. STIERLE, ASSISTANT ENGINEER

UNITED STATES ENGINEER OFFICE
Wilmington, Del., February 3, 1890

GENERAL: I have the honor to submit herewith a report upon the survey of Chincoteague Inlet, Virginia, made under your direction for purposes of a breakwater, and in conformity with the intention of this requirement a project for the location and construction of such a work.

The order directed the survey to be made for the purposes of a breakwater. This was understood to mean for the purpose of establishing a harbor protected by a breakwater. The inlet itself, with its broad channel and mouth to the rear of it, is not available for that purpose. It is too dangerous to enter in rough weather, and full of subsidiary narrow channels with dry intervening banks. It was assumed, therefore, that the scope of the examination was to embrace mainly the deep cove in the shore line immediately north and east of the inlet, and the adjacent sheet of water commonly called Assateague anchorage, which presents many natural advantages for the construction of such a harbor.

The survey was made during the month of August, 1889. I had the good fortune to obtain a boat-crew of picked men, all members of the Assateague Life-Saving Station, whose local knowledge was of great value, and whose steady and intelligent services aided materially in the furtherance of the survey. The most prominent points of the shore were located by triangulation, which commenced at a base line 3,709.70 feet long, measured on Assateague Beach; intermediary portions of the shore were located by sextant angles. The shore line was thus accurately located, and extended on the north side of the inlet from a point due east of Assateague Light to the fish factory, inside the inlet ; and on the south side from opposite this factory to the life-saving station on Wallop's Beach. The hydrography of about 12 square miles of water immediately south of the shore was examined, and mid-depth current observations were made at various points within this area, at both flood and ebb tide. Two tidal stations were established, one just inside of Assateague Channel, where observations were made from August 9 to 31, and one in Power's Cove, back of Fishing Point, where observations were made for seven days.

The mean rise and fall of the tide at the former gauge for the period of observation was 3.41 feet; at the latter gauge 3.45 feet. The average duration of flood is six hours and eight minutes; the average duration of ebb, six hours and seventeen minutes. During the surveys of Chincoteague Shoals, made in 1881 and 1887 by the Coast Survey Department, a tide-gauge had been established about one mile inside of Chincoteague Inlet. The rise and fall of the tide as determined from about one month's observations the first year and from about one-half of a month's observations the second year, was 3.19 and 2.64 feet respectively. It was the intention to compare the mean low-water plane established by the Coast Survey Department with that of the present survey, but the bench marks had been destroyed some time since by the rebuilding of the wharf where they had been located.

The soundings were reduced to mean low water of the gauge in Assateague Channel. This mean low water is probably from two to four-tenths of a foot lower than that used by the Coast Survey Department, assuming in all cases the plane of mean
sea-level (half tide) to be the same. For future reference, however, a permanent bench-mark was established near the gauge, which is 8 feet above zero or 6.88 feet above the mean low water of August, 1889.

Only four days were sufficiently calm during the progress of the survey to permit of current observations to be made. These were necessarily limited to a small section of the very large area that had to be examined and were made principally along the interior of the outlying shoals and Fishing Point, the space that appeared at first sight to be most available for a harbor. A weighted tin can, reaching as near as practicable to mid-depths, was suspended on a fine cord from a small surface float and set adrift at different stages of the tide. The course of the float was located at stated intervals by sextant angles and the time which elapsed between the different stations noted. The direction and velocity were thus readily ascertained on the chart after being plotted.

The set of the flood current south of Turner's Shoal is in a northwesterly direction, turning sharp to the southwest after entering the anchorage. Between Turner's Shoal and Fishing Point the same current enters in a westerly direction and spreads to the northward after passing the point, the stronger drift going up along the inner shore of Fishing Point. At none of the stations where observations were taken did the mid-depths velocity of the flood current exceed .07 of a foot per second. The direction of the ebb current is everywhere north of a line drawn from Turner's Shoal to the bar at Chincoteague Inlet parallel to the general direction of the shore, with velocities varying from .01 to .08 of a foot per second, the strength increasing only toward the last stages of the ebb simultaneous with a decided set in the direction of the gap between Turner's Shoal and Fishing Point.

A comparative chart accompanies this report (Sheet No. 2), which shows the changes that have taken place during the past forty years in the shore-line around Assateague anchorage and Chincoteague Inlet and during the past eight years in the most characteristic contours of the bottom. This chart most clearly shows a rapid increase, in a southwesterly direction, in the growth of Fishing Point, a promontory of quite recent formation on the east side of the anchorage. Since 1850 this point has advanced 2 1/4 miles. In that year the high-water line ran across the base of the present point in an easy curve, scarcely showing any indications of a point, except under water. A survey of the shore made in 1872, locates the well-developed hook of the point already one mile to the south of the shore of 1850. Subsequent surveys enable us to measure the growth more accurately. The extension seems to follow a perfectly straight line, when drawn through the extreme points of the different surveys, which makes an angle of 12 1/2 degrees with the true meridian, and amounted to 3,450 feet between the years 1872 and 1881 and to 2,520 feet from 1881 to 1889, or on an average of about 350 feet per year. With its advance the extreme end has become more acute, though the general width to the rear has nearly doubled since 1881 and is now about 2,000 feet.

The long stretch of concave shore to the north of the anchorage appears to have remained stationary until 1881. Since that year it has also advanced about 900 feet from the middle to the western end of Assateague Channel. The general configuration of the mouth of this channel and along the northeast shore of Chincoteague Inlet has changed but little, with the exception of the extreme westerly point, where the fish factory is now located, which has been cut away by the ebb current 600 feet. The shore southwest of the inlet appears to have advanced some, though the differences shown by the chart may have arisen from the fact that the shore being very flat, a slight rise or fall of the water-level at the time the different surveys were made would necessarily move high-water mark several hundred feet in or out, as the case may be. The shore along Wallop's beach has practically remained the same.

A comparison of the contours of the bottom between the years 1881 and 1889 discloses a general shoaling throughout the anchorage below the 6-foot depth. All the contours have moved southward; the 24-foot curve the most, and in a direction nearly coincident with that of Fishing Point. This movement is equivalent to a reduction in depth of from 2 to 3 feet within the time named.

By the courtesy of Capt. J. T. Tracy, keeper of Assateague Life-Saving Station, I was enabled to obtain certain valuable data in relation to the prevailing winds on this part of the coast. A record of the weather has been kept here for many years. Unfortunately, however, this record lacks method for want of a scientific basis. Particularly is this the case with reference to the force of the wind, which is recorded from individual impressions only and not upon a fixed scale, as adopted elsewhere, which would be of more practical value. I have selected from the long record kept by the captain the daily observations about the wind for the five years from 1884 to 1888, inclusive, and after a patient investigation to get at his personal equation as to the meaning of the force of the wind as entered into his journal, which contained such inapposite terms as "moderate gale," "strong breeze," etc., a classification of the wind was made, embracing five groups, viz, calm, light, moderate, strong, and gale, which is supposed to be approximately correct.

According to this table there occurred during these five years nine calm days; on ninety days the wind was light, on six hundred and thirty fresh, on one thousand and two strong, and on ninety-six days a gale was blowing. Of the latter, which together with the strong winds are of more importance in connection with the subject-matter of this report, twenty-seven were from the northwest, thirteen from the northeast; the next lowest number, eight each, from the south-southeast and west-;northwest; seven each from the south and north-northeast; the remainder being nearly equally distributed over all points of the compass, except that there was none from the east. The prevailing direction of the wind was in the following order for those above the average: Northeast, northwest, southwest and south-southwest. Taking, however, the means of four successive points of the compass all around, to eliminate any possible error arising from a too close habit in the observer to adhere too much to certain directions, the prevailing winds appear in four groups in the following order: From the south to west; north to east; north to west; and south to east.

A compilation of the strength of the wind was made in a similar way after a certain mean velocity had been fixed upon for the days -- classified as light, moderate, strong, and gale. The square of the mean velocity multiplied by the corresponding number of days gives the total wind pressure from a certain direction. The result showed that the greatest total pressure occurred from the north to the west, upon which follow the quadrants from the south to west, north to east, and south to east. Taking each point individually, however, the strongest pressure occurred from the northwest, northeast, and south, in the order named. With few exceptions, the course of the gales recorded was "with the sun," and rarely comprised more than one-quarter of a circle.

It appears that the demand for locating a harbor of refuge on this part of the coast has been entertained for many years. The necessity arose mainly from the long unbroken coast line between Cape Henlopen and Cape Charles offering no place for shelter in case of storms suddenly arising. In such an emergency the smaller class of vessels have heretofore taken and still take the risk of anchoring in Assateague Cove; the larger class stand to sea, or turn back to the capes. It is assumed, therefore, that the benefit to be derived from the construction of a harbor of refuge at this inlet would principally affect the small vessels engaged in oystering, fishing, and trading in and out of the many inland bays of the adjoining coast, and also the larger vessels, commonly called coasters, which navigate along the Atlantic coast and embrace steamers as well as sailing vessels. There is no reason, however, why also the vessels sailing to and from foreign countries should not avail themselves of such an opportunity for a stopping place to wait for or receive orders, situated, as it would be, about mid-way between Baltimore and Philadelphia.

Considering all the physical conditions as described above, the site is not a very eligible one for the construction of a harbor of refuge except at great cost. It is in its greater portion exposed to the severest gales, which generally occur from the northeast to the southwest. The shore is so flat that it offers no shelter against the gales blowing from other points of the compass. The very outline of the shore indicates its unfixed character, its state of transition, causing an unfavorable interference in the littoral currents, which creates the counter-currents that make the cove back of Fishing Point the depositing ground for the material transported up and down the shore by the waves and currents. There are, however, two very favorable features which this site possesses. First, the character of the bottom, especially in the deeper portions, is such as to give a firm holding-ground for anchors; and second, within its borders are two outlets of Chincoteague Bay, an immense natural reservoir for scouring purposes.

It would appear from the above that the construction of a harbor inside or north of a line extending from Fishing Point to the northern point of Chincoteague Inlet would be followed immediately by its own destruction. The counter currents and action of the waves that keep this cove now comparatively free from deposits would be excluded and shoals would form under the lee of Fishing Point and any works that might be constructed. This cove presents at first sight many advantages, and is now, as above stated, the anchoring ground used by small vessels; but it is clear that any change, artificial or otherwise, made in the conditions surrounding its present state must produce effects detrimental to the purpose under consideration.

An area more suitable for a harbor exists within the deep-water pocket which enters immediately west of Turner's Shoal. Although the same objection may be applied in a certain degree to this portion as to the others, it is nevertheless already measurably beyond the prevailing pernicious influences of the currents and susceptible of more permanent improvement.

The project herewith submitted provides for a breakwater running westerly from Turner's Shoal, and for two shore jetties, one to extend from Wallop's Beach in an east-southeasterly direction, the other to be built along the line upon which Fishing Point is advancing. The points principally kept in view in locating these works are: To shelter the anchorage from the heavy seas rolling in from the ocean; to leave an entrance on the east and west side of the harbor through which the currents may pass in their alternate motion and to allow vessels to make harbor under any wind; to provide for the possibility of future shoaling by keeping the location well off-shore; and lastly, to direct as near as is possible under the present conditions the ebb current flowing out of Chincoteague Inlet in such a manner that the largest body at least will go out through the channel in the gap between Turner's Shoal and Fishing Point.

The total length of the breakwater is 12,000 feet. Its general direction is normal to the prevailing direction of the waves. The heavy ocean swell never enters this indentation in the coast line from the east, as will be made clear by the inspection of a coast chart of this section. There exists a peculiar formation of reefs off Fishing Point, extending from south-southwest to east-northeast for a distance of about five miles from the shore. These reefs are known under the name of Chincoteague Shoals, and are curvilinear in form and parallel to each other, their convex side being presented to the ocean. They follow each other at almost regular distance, their radii having a common center, which lies on shore about 1 1/2 miles back from the present extreme end of Fishing Point. During any storm and strong winds that blow towards, and even up and down the shore, the long line of waves break over these shoals on encountering them; the portions not meeting with any obstacle continue with an apparent accelerated velocity in the deeper water south of the shoals and their northern end being retarded, the waves gradually wheel around, resulting in a change of direction almost due north when arriving behind Turner's Shoal, and often nearly into "the face" of the wind.

For these reasons the direction of the breakwater was established as indicated, and it has in this position the further advantage of presenting the least obstruction to the flow of the littoral currents. The main portion consists of two long, central arms, one 3,000, the other 6,000 feet long, joining at an angle of 153 degrees measured on the south side. Recent experiences have demonstrated the utility of building long breakwater in this form, with the concave side toward the direction of the heaviest seas, to concentrate their force and movement at and towards the center instead of near the ends where the entrance is generally located. For the same purpose a shorter arm, 1,000 feet long, is added to the west end of the main body at about the same angle of deflection to protect the western or main entrance. From the east end of the longest branch of the breakwater, a shorter arm, 1,200 feet long, is thrown across Turner's Shoal in a northeasterly direction. This section is to prevent partially, in connection with the jetty from Fishing Point, the projection of waves into the harbor during easterly and southeasterly gales.

The jetty extending from Wallop's Beach may be said to answer two important purposes: First, to arrest the progress of the material drifting northwardly along the shore to prevent further encroachments upon the harbor from that direction; and, second, to create still water over the bar of Chincoteague Inlet, and in a measure to assist the ebb current in deepening it. The length of the jetty as proposed is 10,250 feet. The jetty thrown out from Fishing Point is to protect the harbor on the east against both wind and waves. The length as laid down on the chart is 4,900 feet. It is located nearly in prolongation of the axis of Fishing Point, upon which the latter is still advancing to assist nature's work, although it is possible that since its construction would introduce an element of disturbance in the present regimen, in connection with the other purposed works, it may be necessary to build it out with great caution, and to watch the effects continually, with the view of changing its direction if necessary. The same maxim of cautious proceeding holds good for the breakwater as well as the jetty on Wallop's Beach.

The estimate given below is for works 25 feet wide across the top and extending to a height of 14 feet above mean low water.

The material proposed is a hearting of rubble-stone covered with larger stones, laid with some regularity on the outside. The inner slopes to be generally at the rate of 1 foot in 1, the outer slopes to be 1 to 1 from the bottom up to low-water level, 1 in 6 to high-water level, and then perpendicular breastwork to the top. That portion of the slope on the outside, between the levels of low and high water, is to be particularly re-enforced with heavy blocks not less than from 10 to 20 tons in weight.

For information concerning the extent of the local commerce of Chincoteague Inlet and Bay, I would respectfully refer to the report upon the preliminary examination; to what extent the general commerce along the Atlantic coast would be benefited by the construction of this harbor has also been stated therein and in this report. It may be stated here, in addition, that Chincoteague Inlet is to form the southern terminus of the inland water-way now in process of construction between Chincoteague Bay and Delaware Bay, and its improvement receives, therefore, additional importance.

Estimate: (a) For a breakwater 12,000 feet long; (b) for a jetty at Wallop's Beach 10,250 feet long; (c) for a jetty at Fishing Point 4,900 feet long. Total number of cubic yards of stone, 1,260,896 at $3 per cubic yard, $3,782,688.

Very respectfully, your obedient servant,

A. STIERLE,
Assistant Engineer.

GEN. WM. F. SMITH,
U.S. Agent.

IMPROVEMENT OF CHINCOTEAGUE INLET, VIRGINIA.
Washington, DC
February 14, 1890