Secondly. The mechanism is reasonably simple and certain in its action.

Third. The speed is excellent, and while it is not probable that this or any other known form of controllable torpedo could be successfully operated in a heavy sea, it is also probable that in a moderate sea way and with waves 2 or 3 feet high the torpedo could be guided as far as it could be followed by the eye of the operator.

Fourth. The range could be increased by the methods referred to, but it is already about as great as could be utilized, on account of the extreme difficulty of following up the torpedo and judging of its posi tions with relation to the vessel it is sent after, even in smooth water. Seeing two large vessels, at a mile and a half distance, and not in line with the observer, approach each other, it is very difficult to tell, without the use of instruments, whether they will pass to the right or left of each other, and with nothing but two small flags visible, as is necessary in case of a controllable torpedo, the problem is even more uncertain. With an elevated point of observation this difficulty may be in a measure overcome and a longer range be made practicable.

Fifth. There appears to be no difficulty in guiding the torpedo within the limits above mentioned, and, while the Board has not yet seen any test of its capacity for making sharp curves, it is probable, from the great length and speed of this torpedo, that it will not curve on a very short radius, and it is not as necessary that it should do so as in the case of a slower moving torpedo. In fact, for the reasons above stated, it will generally be desirable to keep the torpedo as nearly as possible in a straight line between the observer and the object.

Sixth. The charge of 200 pounds of dynamite is deemed ample for this kind of torpedo, but could be increased if desired. If in contact with a ship, it will be practically certain to destroy it, and if not in contact, or nearly so, a very much larger and an unknown quantity would be required. It is better to make sure of contact than to try to operate at an uncertain distance.

Seventh. The cost will probably be very considerable, though the Board is not informed as to the amount. The different parts of the mechanism (engines, valves, polarized relays, etc.) will doubtless require the same degree of skill as is required to construct a locomotive, a dynamo, or other similar machinery.

Eighth. For storage the torpedo would have to be taken apart, carefully coated with oil, lead, and tallow, or similar protective against corrosion, and stored in a dry warehouse.

Ninth. It could only be handled safely by men thoroughly familiar with its construction, and with the handling of high explosives. There will always be more or less danger in handling such apparatus, though the safety devices already described would appear reasonably secure. Tenth. This torpedo is not arranged for diving under booms, nor, like the Berdan, for secondary explosions, to destroy or penetrate safetynetting.

The inventor proposes to use them in sets of two or more, so that one can clear the way for the others; but the success of this plan must be considered doubtful on account of the unknown extent of the damage that would be done to a ship's protecting net or booms by the first explosion, and the difficulty of directing the second torpedo into the hole made by the first one.

This objection, however, applies to all movable torpedoes with the exception of the Berdan type, which is designed to cause the second or

towed torpedo to dive under the net; but this plan has not, it is be lieved, been practically tested.

The conditions imposed upon Auto-Mobile controllable torpedoes are to a certain extent incompatible, and it is hardly to be expected that any one torpedo will fulfill all of them perfectly; but it is the opinion of the board that the Patrick torpedo possesses these requirements to a degree that makes it worthy of consideration and trial, when funds are available for the purchase of such weapons. W. R. KING,

Major of Engineers.
EDWD. MAGUIRE,

Gaptain of Engineers, U. S. A.
S. W. ROESSLER,

Captain of Engineers.

IRVING HALE,

First Lieut. of Engineers.

RIVERS AND HARBORS, ETC.

APPENDIX A.

IMPROVEMENTS OF RIVERS AND HARBORS IN THE STATES OF MAINE AND NEW HAMPSHIRE.

REPORT OF LIEUTENANT-COLONEL JARED A. SMITH, CORPS OF ENGINEERS, OFFICER IN CHARGE, FOR THE FISCAL YEAR ENDING JUNE 30, 1889, WITH OTHER DOCUMENTS RELATING TO THE WORKS.

GENERAL: I have the honor to transmit herewith annual reports for the fiscal year ending June 30, 1889, for river and harbor works in my

Very respectfully, your obedient servant,

The CHIEF OF ENGINEERS, U. S. A.

ΑΙ.

IMPROVEMENT OF LUBEC CHANNEL, MAINE.

During the fiscal year no' work of improvement has been carried on. At the beginning of the year the available funds amounted to but $10.03, and all work under former contracts had been completed.

By act of August 11, 1888, Congress appropriated $20,000 for continuing the improvement. The estimate for entire completion of the work, obtained by subtracting amounts appropriated from original estimate for the entire work, was $22,500. The average of prices obtained have been slightly less than the estimates, so that the amount of the last appropriation will be sufficient to complete the work as heretofore approved.

The lateness of the season when the appropriation became available, together with the time necessarily consumed in complying with formalities required by law and regulations, made it impracticable to commence dredging before the spring of 1889.

Under date of December 13, 1888, advertisements were issued inviting proposals for the work of widening the channel by dredging.

A contract for the work was let to Augustus R. Wright, of Portland, Me.

This contract, approved February 23, 1889, requires the contractor to commence work on or before October 1, 1889, and to complete the work on or before June 30, 1890.

When completed the channel will have a depth of 12 feet, a width of 275 feet throughout, and 25 feet additional width at the bends.

The total length of channel in which the improvements have been made is approximately 11,000 feet. Commencing at the narrows the natural channel for about one half the distance is straight, and is somewhat wider than the excavated channel over the other half of the distance to Quoddy Bay and anchorage.

The dredged channel is in the shape of a flattened letter S, the two bends requiring a change of direction amounting to 55 degrees and 52 degrees, respectively, in going out to sea. The bends are short and as the tides have a range of 17 feet or more, with consequent rapid currents, such a channel is very difficult for sailing vessels to navigate, and in low stages the masters of steamers prefer to make the long passage around Campo Bello Island rather than to incur the risk of running upon the banks of the cut.

The channel is a thoroughfare to various points on our eastern coast, as well as a factor of safety for the anchorage in Quoddy Roads when the wind changes to easterly points. Local statistics are therefore very incomplete, and there is no means of ascertaining the exact number of passing vessels. In 1882 a record was kept of about 10,000 vessels passing Quoddy Head light-house. No subsequent record has been kept. A record of vessels seen to pass the life-saving station at Lubec in 1887, in day-time and clear weather, shows the number to be 8,683.

Lubec is in the collection district of Passamaquoddy. The nearest port of entry is Eastport, Me. The nearest light-house in the United States is on West Quoddy Head, about 7 miles below.

There is a Canadian light-house on Mulholland's Point, at the narrows opposite Lubec.

The following appropriations have been made for improving Lubec Channel:

July 1, 1889, amount expended during fiscal year, exclusive of liabilities outstanding July 1, 1888...

$503.26

July 1, 1889, amount covered by existing contracts..

July 1, 1889, balance available..

1,506.77

Abstract of proposals for dredging in Lubec Channel, Maine, opened January 10, 1889.

The contract was awarded to Augustus R. Wright, and dated February 7, 1889.

35

COMMERCIAL STATISTICS.

The following statistics, for the year ending June 30, 1889, were furnished by the United States collector of customs for the Passamaquoddy district: