The soundings in the harbor of Edgartown given upon the accompanying chart exeented by Marindin differ from those which appear upon the chart of Lieut. Charles H. Davis (dated 1846) in three localities of limited extent:

1st. One foot more water can now be brought into the town basin over the bar. 2d. The apron of sand within Chappaquiddick Point has extended so as to reduce the depth all the way across the channel and impair the holding ground. The cross-section most encroached upon has lost about 25 per centum of its area.

Mr. Mitchell ascribed the first, a change of 1 foot on the bar, to the work of years, as it had not been noticed by the people at Edgartown. The second, a loss of 25 per centum in section inside of Chappaquiddick Point, he inferred was recent and due to the absence of an opening through the South Beach, which had closed in October, 1869, a little more than a year before, because it had attracted their attention since. The absence of any data as to the condition of the harbor just prior to the closing of the beach makes the determination of the causes which produced the change of section noted by Mr. Mitchell uncertain.

Whatever changes occurred in the eighteen months prior to the survey of 1871, it is probable that they have continued, the natural conditions remaining the same, so that they can better be measured by the results of subsequent surveys.

The map of the survey of the harbor made by Mr. Van Ingen, the assistant on this work in 1874, is very thorough and elaborate, insomuch that the one of 1871 is too general for reliable comparison at special points to determine the changes from 1871 to 1874. A comparison, however, was made by Mr. Van Ingen, reported as follows:

A more rational comparison of these maps leads us to the conclusion that the only changes that have taken place between 1846 and 1871 are such as have been occurring for years, and consist of the slow extension of Chappaquiddick Point and the filling in south of it. That there is not sufficient evidence of any change having taken place between 1871 and 1874; that if there was any it was one of improvement rather than a detriment.

The differences reported between 1846 and 1871, outside of Chappaquiddick Point, Mr. Van Ingen thought might be ascribed to omissions or error in survey. The decrease of area inside of the point since 1846 was the only certain change, and that had not continued from 1871 to 1874.

The survey of 1874 gives the condition of the harbor after the opening in South Beach has been closed four and a half years. The survey of 1881 enables us to measure the changes of the last seven years.

Comparisons. It is discovered in following the line of deepest water in the maps of the surveys of 1871, 1874, and 1881 that there has been no decrease in the depth. In comparing the map of the survey of 1871 with that of the survey of 1881, the first point of difference is found in the shoal near the light-house. The 12-foot curve on the north side of this shoal has on the easterly end moved northward about 100 feet for a distance of 300 feet. Northeast of the light this curve has moved in or deepened for about 200 feet. These changes, however, are not to exceed a foot in depth in either case.

South of the light and for a distance of 600 feet in towards the shore there has been considerable scour. Where in 1871 there was 6 feet depth there is now 15 feet, and where there was 12 feet there is now nearly 18 feet. The bank where this scour has taken place is steep, so that this increase of depth is over but a limited area.

In the angle of the causeway or bridge leading to the light and the shore there is less depth than in 1871, the 6 and 12 foot curves having moved out about 100 feet.

In the outer or northerly end of the pool of deep water along the wharf fronts there has apparently been some filling, amounting in one place to 2 feet.

Off the northwest part of Chappaquiddick Point there has been a marked increase of depth; the 18-foot curve is now fully 75 feet nearer the high-water line than in 1871. Where there was 9 feet depth there is now 18 to 20 feet. After passing inside of the point there has been a double change, the area of deep water (18 feet) has increased, and that of shoal water (less than 6 feet) has increased.

The next change is found in an increase of depth on the west side of the channel opposite the northerly part of the "Middle Ground." Here for a distance of from 400 to 500 foot the 18-foot channel has increased in width from 100 to 200 feet. On the "Middle Ground" there seems to be an increased depth, but not enough soundings were taken this year to make this conclusive.

Before reviewing the changes above noted let us compare the map of 1874 with that of this year, 1881. The first difference noted between the map of survey of 1871 and 1881-the increase in width of the Lighthouse Shoal at its easterly end-does not appear in these maps. The same deepening northeast of the light may be seen on the map of 1874. The increased width of the deep water south of the light is evident on this map of 1874, also the filling in the angle between the causeway and the shore. The increased depth to the northwest of Chappaquiddick Point, and the increased width of the deep water inside of the harbor are apparent. The increase of the shoal-water area is shown, but it is not so evident as it is on the map of 1881. The area inside of the 6-foot line on the " Middle Ground" is less than in 1871, while the 12-foot line includes nearly the same area. These differences are mostly of small extent, and some of them are within the limit of the error in sounding. The unmistakable changes are:

1st. An increase in the width of the 15-foot channel from the light for 600 feet towards the wharf.

2d. A decrease of depth in the angle made by the causeway to the light and the shore.

3d. An increase in width of the 18-foot channel opposite Chappaquiddick Point.

4th. An increase of the width of the 18-foot channel inside the point. 5th. An increase of the shoal-water area inside or under Chappaquiddick Point.

The increase in depth, while considerable, is over a limited area, and not likely to be noticed except by comparing the results of surveys made at intervals of several years. The shoaling at the angle of the causeway and shore, and under Chappaquiddick Point, covers considerable area, there being but little depth of water there, and its progress has been evident to those frequenting the locality in small boats.

Cross-sections of the harbor measured on the maps of 1816, 1871, 1874, and 1881 are given below. No. 1 is from the Light House to Chappaquiddick Point. No. 2 is from the causeway at a point 485 feet from the light and at a right angle thence to Chappaquiddick Point. No. 3 is from the angle of the causeway and parallel to Nos. 1 and 2. No. 4 from the northeast corner of the wharf nearest the light to Chappaquiddick Point. No. 5 is from Darrow's Wharf to Chappaquiddick Point and

No. 6 from the point in a southwesterly direction.

This last is the sec

tion used by Mr. Mitchell in the comparisons in his report.

The cross-sections of 1871 are taken from the published chart; the small scale of this map and the limited number of soundings on it make the calculations of areas less reliable than those on the maps of 1874 and 1881.

On section No. 1 the area seems to have been greater in 1874 than in either 1871 or 1881. On section 2 there has been a small increase from 1871 to 1874 and also from 1874 to 1881.

On section 3 the area has diminished slightly since 1871. On section 4 there was a slight increase from 1871 to 1874 and a greater increase from 1874 to 1881. On section 5 there is a slight increase from 1874 to 1881. On section 6 there has been an increase from 1871 to 1874 and a smaller increase from 1874 to 1881. These changes are not large, and might be attributed to errors in making or platting soundings, if they did not show the same changes going on between 1874 and 1881 as between 1871 and 1874, save in the case of the first section.

From the foregoing study of the maps of 1871, 1874, and 1881 the following conclusions are reached:

1st. That the ruling depth into the harbor of Edgartown has not changed since the closing of the southern entrance to the harbor, nor the section of tidal flow diminished.

2d. That the width of the 15-foot channel has increased in the narrower portions of the channel.

3d. That there has been a decrease in depth in the sheltered angles southwest of the light near the shore and under Chappaquiddick Point, where there is little current and such siltings are unavoidable.

4th. That the changes have not been of such extent as to make us apprehend by their continuance serious injury to the harbor.

The data upon which these conclusions are based have been submitted to the Massachusetts Land and Harbor Commission.

While there is no specific difference in our opinion and theirs as to actual changes in the harbor, they are still apprehensive that the closing of the beach has destroyed certain beneficial influences, which may result in injury to the harbor. As it is best to be on the safe side in such matters, I give their opinion, that due weight may be given to their view of the situation.

NEW PROJECT FOR OPENING THE BEACH.

The opening that was made in 1873 was made at the western end of the beach, under the belief that if it enlarged so as to become an inlet it would gradually move eastward and close as the last one had done. The western location thus promised a longer existence for the inlet. The present location near the eastern end would allow of but a comparatively short period if the inlet formed and moved as the natural ones

had done. It is therefore proposed to hold it in position by means of a jetty on the west side of the opening.

The width of the channel through the inside shoal, to allow the ves sels in use to beat, need not exceed 200 feet. This is the greatest width of the existing channel. It will have to be widened in places, and considerably deepened in other places by dredging, to make 4 feet at mean low-water. To work the scows and tug we shall have to make a depth of 6 feet, for a width of 60 feet, at mean low-water.

It does not now appear that the width of the beating channel need be any greater than 200 feet for the permanence of an inlet.

The wider, however, we can make the opening in the beach the better the chances of its becoming an inlet, and a cut 300 feet wide, 6 feet deep at mean low-water, is what is proposed, all to be done by dredging. The place on the beach selected by the committee is shown on the map near the former opening of 1846. It will be so marked off that the west side, or west chop (if it becomes an inlet), shall not be less than 500 feet from Chappaquiddick Island. This is the width of the narrowest natural inlet described by Mr. Whiting. That one we know succumbed in its battle with the waves and sands, but it sustained the contest alone, and it is proposed in the future to aid it in resisting encroachment in the best way we can.

The line of the channel and the new opening are shown on the map.

For pile jetty, 200 feet long, with apron of brush and stone..
For landing at beach road across beach and buildings....
For transportation of men and materials from Edgartown to beach.
For superintendence and engineering......

Total.....

10,500

800

1,000

2,500

39,050

This work should all be done in one season, so that it is of great importance to have the whole amount of the estimate before beginning the work.

INCREASE OF ANCHORAGE.

There are two wrecks of lime-laden vessels lying in the harbor, which disfigure it and diminish the anchorage somewhat. The complete removal of these will probably cost $750 each, or $1,500 for both.

They have lain there for over ten years, and the opening of the beach should have preference over any improvement of this kind for increas ing anchorage. Under this head may be included dredging away the "Middle Ground," which is not now urgent.

IMPORTANCE OF AN INLET THROUGH SOUTH BEACH.

This is a question that cannot easily be answered. Over one thousand vessels a year anchor in the harbor, which has well accommodated them so far, and there does not appear a present demand for more space. The harbor maintains its good character without the inlet, and the benefit of the latter must be mainly confined to the fishing interest and to

piloting off the south shores. The desirability of preserving all interests and channels for the making and support of seamen is important to the nation. The closing of the inlet was a great local injury to these people, which they cannot repair, and it deserves a liberal action on the part of the government to aid them by restoring it. The value cannot well be estimated in money, but it has been well said that the services of one pilot using the inlet may readily prevent loss of property and life that would be more than a return for the whole outlay.

Edgartown is in the Edgartown collection district, and is a port of entry. The amount of revenue collected there during the fiscal year ending June 30, 1881, was $1,618.64.

The surveys and maps have been made by and under the direction of Assistant J. P. Cotton, whose energy and experience enabled him to do this work at much less than usual cost. Foggy weather prevented the surveys being made as complete as they would otherwise have been. Accompanying this report are the following maps, viz:

(1.) A tracing of the United States Coast Survey Map of Edgartown Harbor and Cotamy Bay, Massachusetts, by H. L. Whiting, H. Mitchell, and H. L. Marindin, in 1871, with a few additional notes. This is marked II. Scale, Too

(2.) A tracing of map, made in 1873, of Edgartown Harbor, Massachusetts, by H. S. Van Ingen, assistant engineer, under direction of Bvt. Maj. Gen. G. K. Warren, U. S. Army, with additional notes. Scale, 200 feet to 1 inch. This is marked and referred to as III.

(3.) A tracing of map, made in 1874, of Edgartown Harbor, Massachusetts, by H. S. Van Ingen, assistant engineer, under direction of Bvt. Maj. Gen. G. K. Warren, U. S. Army. Scale, 200 feet to 1 inch. This map is marked and referred to as IV.

(4.) A tracing of the map of the survey made of Edgartown Harbor and South Beach, Massachusetts, in 1881, by Joseph P. Cotton, assistant engineer, under direction of Bvt. Maj. Gen. G. K. Warren, U. S. Army. Scale, 200 feet to 1 inch. This map is marked V.

No. 1 of this series was made under direction of Gen. George Thom, U. S. Engineers, in 1872. It is on file in the Engineer Department at Washington, D. C.

Respectfully submitted.

Brig. Gen. H. G. WRIGHT,

Chief of Engineers, U. S. A.

B 15.

EXAMINATIONS AND SURVEYS OF BUZZARD'S BAY AND BARNSTABLE BAY, MASSACHUSETTS, AT THE ENTRANCES OF THE PROPOSED CAPE COD CANAL.

ENGINEER OFFICE, U. S. ARMY, Newport, R. I., February 3, 1882. GENERAL: I submit herewith my report upon the examinations and surveys, with estimates of cost of improvements proper to be made at the entrances of the proposed Cape Cod Canal between Buzzard's Bay and Barnstable Bay, Massachusetts. This was authorized at the close