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and the strong cross-current. There is a narrow, crooked channel between Red and Dry Ledges with about 7 feet of water; this channel, I believe, is never nised.

Middle Channel, between Lone Rock ou east end of Dry Ledge and Grassy Island, bas about 10 feet depth, at mean low water, for 100 feet in width; this is the channel principally used by sailing-vessels, and the only one for which the Coast Survey chart gives saising directions.

North Coannel, between Grassy Island and Devil's Foot Island, has abont 10 feet depth for a width of 200 feet. This channel is used only by those who are familiar with the set of the currents here.

Middle Channel, in following it through from the east, is obstructed by a rock about 400 feet from the entrance with 7.9 feet on it at mean low water. From the east end of Devil's Foot Island a reef of bowlders makes out into the channel and entirely across the channel marked out on Coast Survey chart, with 11.5 feet on its deepest part; a rock on the south end of this reef has 7.8 feet on it at mean low water. To the sonth of this rock there is 20 feet depth.

The next obstruction is Middle Ledge; here the channel is about 150 feet wide, with 15 feet of water. This is a bad obstruction in the swiftest current, with deep water east and west of it. It is marked by a can buoy.

Imniediately west of Middle Ledge, in the channel, is a shoal with 13.5 feet of water on it, and 20 to 27 feet all around it.

Some 1,500 feet west of the buoy op middle ledge there is a shoal bare at low water; about 300 feet northeast of this are three bowlders, with 7.7 feet on them at mean low water. The name " Entering Rocks" is given by some to the shoal, and by others to these bowlders. About 1,500 feet west of these rocks there is a rock with but 9 feet on it; it is in about 16 feet of water.

Broad Bay is obstructed by two or three bowlders, with less than 10 feet on them.

There is a narrow channel between Middle Ledge and Pine Island, with 14 feet of water, but this is obstructed by a cluster of bowlders with less than 1 foot on them at low water. If these were removed it would still be impracticable, because it is in the middle of a broad expanse of water, and could only with great difficulty be found in the night or in foggy weather.

The obstructions in the “Hole” are so great that sailing-vessels attempt its passage very rtrely, aud then only on or near slack water.

À line of steamers between New Bedford and Martha's Vineyard make a trip each way daily, and in summer two trips each way, through this strait. These steamers carry freight and passengers, but their chief business is the carrying of passengers. The largest boat of this line draws 8 feet. The channel used by them has several bowlders, with less than 9 feet at mean low water. These in a low run of spring tides bave less than 8 feet, and on them these boats have strnck repeatedly. On oue occasion a boat with 600 passengers struck on one of these rocks and was disabled. All were safely Janded in yawl-boats. These boats go through the “Hole” at all times of tide and in all kinds of weather.

There are fonr boats belonging to this line, valued at $200,000. They make aboat 800 trips through the “ Hole” yearly, and from November 1, 1872, to November 1, 1973, carried 58,924 passengers and about 1,000 tons of freight. The officers of this company think that if the bowlders lying in the channel were removed, and a few from the point of Middle Ledge taken off, they would have but little difficulty in making the passage of this now dangerous strait.

I have made an estimate for removing the few bowlders that these boats frequently, strike. Besides this I have made several estimates with the view of making the use of this channel practicable by the vast coasting fleet that now passes through Vineyard Sound.

First. To remove the Entering Rocks, a few bowlders from the point of Midille Ledge, and two or three from Broadway that are serious obstructions to the navigation of the “Holo” by the New Bedford and Martha's Vineyard steamers, $5,000.

Second. To reinove the bowlders as in first estimate, and all those in the channel passing Lone Rock, so as to give 200 feet in width clear of rocks, and widen the channel at Middle Leilge to 200 feet by taking the bowlders off the point of the ledge, $22,000. With this amount the channel can be much improved, and it is possible that if the bowlders are removed that the current will deepen the channel somewhat. A less amonnt than this will not be so economical, as the necessary apparatus for doing this work will reqnire considerable out.ay.

Third. For a channel 9 feet deep at mean low water, and 300 feet wide at Middle Ledge, 400 feet wide at the bay entrance, and with three channels at the sound entrauce, each 300 feet wide, and 9 feet deep at mean low water, to costFor removing bowlders...

$22,000 For dredging 18,870 cubic yards clay gravel and bowlders, at $1 Superintendence

Total

18,70 2,000

42,000

This improvement, by giving three wide entrances into the sound, wonld enable sailing-vessels to pass through from the west without danger of being drawn on to the rocks by cross-currents, because they would have a channel in any direction, and could choose the ope that wind and current best suited.

Fourth. For the improvement of third estimate, and the removal of all of Middle Ledge to 9 feet at mean low water, this woulil give a channel 800 feet in width, with threo 300-foot channels, into the sound. With this improvement a sailing-vessel could beat through the “Hole." For removing bowlders, second estimate.

$22,000 Dredging and superintendence, third estimate

20,870 Dredging of Middle Ledge, 59,000 cubic yards, at $1

59,000 Superintendence

6,000 Total .....

107, 970 Fifth. For a channel the same width as in fourth estimate, and 12 feet deep at mean low water. For removing bowlders, second estimate..

$22,000 For dredging and superintendence, third estimate.

20,870 For dredging and superintendence, fourth estimate.

65,000 For additional dredging, 84,530 cubic yards.....

84,530 Superintendence

8,000 Total

200, 400 Sixth. For a channel the same as in fifth estimate, with 300 feet of its width deepened to 15 feet at mean low water, and the three entrances to the sound the same. depth, (15 feet.) For removing bowlders, second estimte....

$22,000 For dredging and superintendence, third estimate..

20, 879 For drenging and superintendence, fourth estimate

65,000 For dredging and superintendence, fifth estimate..

92, 530 For additional dredging,61,500 cubic yards, at $1.

61,500 Superintendence

6, 100 Total

268,000 Seventh. For a channel same as in the sixth, with 300-foot channel increased to 18 feet deep, at mean low water. For removing bowlders, second estimate.....

$22,000 For dredging and snperintendence, third estimate..

20, 870 For dredging and superintendence, fourth estimate.

65,000 For dredging and superiutendence, fifth estimate..

92,530 For dredging and superintendence, sixth estimate.

67,600 For additional dredging, 161,500 cubic yards, at $1.

161,500 Superintendence

16,500 Total

446, 000

RECAPITULATION OF ESTIMATES.

First estimate... Second estimate. Third estimate Fourth estimate.. Fifth estimate. Sixth estimate Seventh estimate..

$5,000 22,000 42,870 107, 870 200, 400 268,000 446,000

COMMERCIAL VALUE OF THIS IMPROVEMENT.

The removal of the bowlders from the channel used by the steamers wonld be of great value to the steamboat company, whose boats use this channel daily; and to the thousands traveling lng them, whose lives are jeopardized every time they make the passage, its value cannot be measured in dollars and cents.

The other estimates have been made with a special view to the wants of the coasting trade, and are arranged in the order that will give the most improvement for the acount expended. Each estimate is for a definite improvement coinplete iu itself, but still a part of the plan for the greatest improvement.

The strait of Wood's Hole separates the Elizabeth Islands from the main-laod, and is about twenty miles from the west end of these islands. These islands are separated from each other by Robinson's Hole and Quixe's Hole, and by two or three small upnavigable ones without names, forming passages between Buzzard's Bay and Vineyard Sound. Robinson's Hole is narrow and so much obstructed by rocks that it is seldom used. Quixe's Hole is a good channel with sufficient depth, and is very much used by vessels going to and from New Bedford, and other ports in Buzzard's Bay, but because of the detour around Penikese Island and a lone rock in the bay, and the comparatively short distance saved, it is but little used by the coasting fleet passing east and west, not so much as it probably would be were it better known.

In Vineyard Sound on the south side of the Elizabeth Islands the tidal cnrrent sets to the eastward about four hours after it has turned and is setting to the westward in Buzzard's Bay, immediately north of them. If the channel through Wood's Hole were improved, a vessel bound west, arriving there when the tide commenced to set east in the sound, by going through the Hole, would have a fair tide four bonds earlier and smooth water, and would, if depending on tide, gain much in time and distance. When a vessel bound east arrives at the light-ship off Cuttyhunk Island, and meets the tide running west of the sound, if the wind is light she can make no headway and must beat about the entrance until the tide changes. If, however, she could go through Wood's Hole she would go to the north of these islands with a fair tide and smooth water four hours before she could get into the sound. Again, if this improvement were completed, two fleets of vessels arriving, one at Cuttyhuok and the other at Wood's Hole at the same hour, woald, in order to have the tide with them, one take the Buzzard's Bay ronte and the other the scund route and avoid all danger of collision if in the night or foggy weather.

The width of Vineyard Sound west of Wood's Hole available for navigation is made less than two miles by that dangerons shoal known as the “ Middle Ground," near the south shore. This shoal is marked only by one buoy on each end, and the uncertainty of seeing these wakes all navigating the sound bug the north shore to avoid it.

They in doing this frequently get aground on the north shore in thick weather and collisions are of frequent occurrence here.

If this improvement were made it wonld probably relieve this channel of nearly one-half the number of vessels now using it, and there would be the further advantage that most of those using it would be sailing in the same direction.

The number of vessels engaged in the coasting trade is very large and annually increasing, and with this improvement made the time saved in the aggregate would be a very large item, and the lessening of the danger of accidents by collision would be. to so large a number, worthy of consideration. To vessels bound to New Bedford from the east this channel, if improved, would save ten miles in distance, and to those to Wareham, pineteen miles.

Wood's Hole is in the Barnstable collection-district. The amount of revenue collected there during the fiscal year was $3,425.

Accompanying this report is a map of the survey, on a scale of 200 feet to the inch; also a chart showing the direction and velocity of the tidal flow through the Hole for an east and west tide, on the same scalo as the map.

Attached to the report is a chart showing four tides in Buzzard's Bay and Vineyard Sound, plotted from the same.

To my principal assistant, Mr. C. R. Mather, civil engineer, I am under special obligations for his valuable services in the field and office. Respectfully submitted.

J. P. COTTON,

Civil Engineer, Assistant in Charge of Survey. G. K. WARREN,

Major of Engineers and But. Maj. Gen., U. S. A.

Tides in Vineyard Sound and Buzzard's Bay,

near Wood's Hole, Mass.

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H. Ex. 8443

6.-SURVEY OF THE HARBOR OF FALL RIVER, MASSACHUSETTS.

This survey was authorized by the act of Congress approved March 3, 1873, and was, as stated in the act, made with a view to the removal of rocks from this harbor.

This survey was conducted by my assistant, Mr. J. P. Cotton, civil engineer, and bis report, with a map, is submitted herewith, to which special attention is invited for complete details of the work. The survey extends along the harbor front about 1,500 feet, between Rodman's wharf and Brown's wharf, and out to the curve of 14 feet depth at mean low water.

The most obvious obstructions in this space are bowlder rocks of all sizes up to several tons' weight; but besides these the surface on which they lie is too shoal and requires dredging.

We have made an estimate for the removal of the rocks and the dredging separately, and also for a few dolphins to mark out the channel when improved and to guide and aid vessels in getting in and out.

The improved channel thus to be provided is to be 12 feet deep at mean low water, and 100 feet wide at the narrowest parts, wideving out at each end, where it joins the main channel.

The estimate is as follows: For removing bowlders.

$11,000.00 For dredging:

33, 400 00 For six dolphins..

600 00

45, 000 00 Fall River City is a most important commercial place, and too well known to need special mention here. It is a port of entry, and the amount of revenue collected in the fiscal year ending June 30, 1873, was $212,491.42. Very respectfully,

G. K. WARREX, Major Engineers, Brt. Maj. Gen., U. S. A.

ENGINEER OFFICE UNITED STATES ARMY,

Newport, R. I., December 22, 1273. GENERAL: I have the honor to submit the following report on the “survey of the harbor of Fall River, Massachusetts, for the removal of rocks therefrom,” made in aecordance with your instructions:

In July I visited Fall River and conferred with the parties who had been instrumental in having this survey ordered, to learn their idea of the obstructions. From this conference and a reconnaissance I found that a survey of that part of the harbor between Rodman's wharf and Brown's wharf, and the curve of 14 feet depth at mean low water, would include all the obstructions and would be all that was necessary to determine the improvements to be considered.

The field-work of this survey was commenced on the 5th and completed on the 15th of September. The survey extends along the harbor front about 1,500 feet, and out to 14 feet depth at mean low water. It was conducted in the usual manner by running a line along the shore. Important buildings and wharves were located by angles and distances. Inaccessible points were fixed by angles taken at each end of a ineasured base line. The position of every station used as an instrument station that had been fixed by triangulation was veritied by repeating all of the angles of the triangle. All of the soundings were located by the intersection of lines of sight from each end of 3 base line on shore, the angle that these lines made with the base being measured with a transit.

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