APPENDIX.

No. 1.

EXTRACT FROM A REPORT MADE IN 1840 TO THE SECRETARY OF WAR BY THE BOARD OF ENGINEERS OF THE UNITED STATES ARMY.

"Means of obstructing entrances to harbors.

"This brings us to consider a third class, consisting of establishments of importance situated at a distance up some river or bay, there being intermediate space too wide to be commanded from the shores. In such cases the defence must be concentrated upon the narrow passes, and must, of course, be apportioned in armament to the value of the objects covered. When the value is not very great, a stout array of batteries at the best positions would deter an enemy from an attempt to force the passage, since his advantage, in case of success, would not be commensurate with any imminent risk. But with the more valuable establishments it might be otherwise; the consequence of success might justify all the risk to be encountered in rapidly passing in face of batteries, however powerful. This condition of things requires peculiar precaution under any system of defence. If after having occupied the shores, in the narrow places, in the best manner, with batteries, we are of opinion that the temptation may induce the enemy, notwithstanding, to run the gauntlet, the obstruction of the channel must be resorted to. By this is not meant the permanent obstruction of the passage; such a resort, besides the great expense, might entail the ruin of the channel. The obstruction is meant to be the temporary closing by heavy floating masses.

"There is no doubt that a double line of rafts, each raft being of large size, and anchored with strong chains, would make it impossible to pass without first removing some of the obstructions, and it might clearly be made impossible to effect this removal under the fire of the batteries. Such obstructions need not be resorted to until the breaking out of a war, as they could then be speedily formed, should the preparation of the enemy be of a threatening nature.

"There would be nothing in these obstructions inconsistent with our use of part of the channel, since two or three of the rafts might be kept out of line, ready to move into their places at an hour's notice.

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The greatest danger to which these obstructions would be exposed would be from explosive vessels, and from these they might be protected by a boom or a line of smaller rafts in front.

"From what has just been said it will be perceived that, when the inducements are such as to bring the enemy forward in great power, and efficient batteries can be established only at certain points, we are not then to rely on them exclusively. In such a case, the enemy should be stopped by some physical impediments; and the batteries must be strong enough to prevent his removing these impediments, and also to prevail in a cannonade, should the enemy undertake to silence the works.

"The conditions these obstructions have to fulfil are these:

"1st. They must be of a nature to be fixed readily, and to be speedily re

moved when there is no longer occasion for them, and to this end they must be afloat.

"2d. They must have adequate inertia to resist, or rather not to be destroyed or displaced by the shock of the heaviest ship; and in order to this they must be held by the heaviest and strongest cables and anchors.

"3d. They must be secure from the effects of explosive vessels; and, if in danger from this source, must be covered as above mentioned. We don't say what are the exact circumstances in which all these conditions will be fulfilled, though we think the idea long ago presented by the board of engineers will, with modifications, embrace them all.

mentum.

"The idea is this: Suppose a line (extending across the channel) of rafts, separated from each other by a space less than the breadth of a ship-of-war, each raft being about 90 feet long, 30 feet wide and 6 feet deep, formed of strong timbers, crossed and braced in all directions, and fastened together in the strongest manner. A long-scope chain cable is to proceed from each of the four corners, two obliquely up stream, and two obliquely down stream, to very heavy anchors; and there should also be a very strong chain cable passing from one raft to another. Suppose a ship striking one of the rafts to break the chains leading down the stream; in doing this, she must lose much of her moShe has then under her forefoot' the raft, connected by a strong chain with the rafts to the right and left; on being tightened, this chain will throw the strain upon the down-stream cable of that adjoining raft towards which the ship happens to tend. If we suppose it possible for these chains also to be parted by the power still remaining in the ship or by impulses received from succeeding vessels, there will be other chains still to break in the same way. After the down-stream chains are all parted, the rafts will bring up' in a new position (higher up the channel) by the anchors that, in the first instance, were pointed up stream. Here a resistance, precisely like that just overcome, is to be encountered by vessels that have lost more of their force in breaking the successive chains, and in pushing these great masses of timber before them through the water. Should there exist a doubt as to the sufficiency of these remaining anchors and chains, or should it be deemed most prudent to leave nothing uncertain, a second similar line may be placed a short distance above the first.

"The best proportions and dimensions of the rafts remain to be determined, but as there is scarcely a limit to the strength that may be given to the rafts themselves, and to the means by which they are to be held to their position and to each other, the success of a well-arranged obstruction of this sort can hardly be doubted.

"The expense would not be great in the first instance, and all the materials would be available for other purposes when no longer needed for this."

No. 2.

[HO REPS., Ex. Doc. No. 153, 19TH CONGRESS, 1ST SESSION.]

REVISED REPORT OF THE BOARD OF ENGINEERS ON THE DEFENCE OF THE

SEABOARD.

WASHINGTON, March 24, 1826.

SIR: In the report now respectfully submitted, in compliance with the order of the engineer department of the 25th ultimo, the board of engineers have attempted to enforce all those leading principles which relate to the defence of the maritime frontier of the United States. In doing this, in describing briefly the several sections of the coast, and in applying those principles to the local pecu

liarities thus developed, the board have been unavoidably led to a repetition of much that is contained in their previous reports. The tenor of the order under which this report has been drawn will, however, cover this objection, if it be one, while the report will have the decided advantage of presenting the prominent features of the whole subject from a single point of view, and serving at the same time as an index to the minute details comprehended in previous communications.

The following is a copy of the order above referred to:

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"ENGINEER DEPARTMENT, Washington, February 25, 1826. "GENTLEMEN: As much information with regard to the maritime frontier has been obtained since the report of the board of February 7, 1821, was made, it is the desire of the Secretary of War that a revision of that report and a new examination of the subject of the defence of the seaboard, including the Floridas, which have since been added to the Union, should be undertaken, with a view to the classification of the several works, including those which have been constructed and those which will probably be necessary to be constructed, and also stating what works may be included in the general system which were constructed before the formation of the board.

"It is desirable that the report be as full and explicit as possible, setting forth the size, number of guns, garrisons for peace and war, cost, objects to be defended, and the advantages to be derived from their position in a military and commercial point of view; the militia that may be assembled within a reasonable time for assisting in the defence of the several positions, and including, in general, everything that is worthy of consideration in the general estimate of the defence of the seaboard and country adjacent or dependent thereon.

"I have the honor to be, gentlemen, &c.,

"ALEX. MACOMB, "Major General, Chief Engineer.

To General BERNARD and Colonel TOTTEN, "Board of Engineers."

The United States, separated from the rest of the world by an ocean on one hand and a vast wilderness on the other, pursuing towards all nations a policy strikingly characterized by its pacific tendency, its impartiality and justice; contracting no political alliances; confining her intercourse with the rest of the world rigidly to the letter of such temporary arrangements as are dictated by reciprocal commercial interests, might at first view be regarded as too remote physically, and as politically too insulated, to be endangered by the convulsions which from time to time disturb the nations of the earth.

Neither our geographical position, however, nor our forbearance, nor the equity of our policy, can always avail us under the relation in which it is our destiny to stand to the rest of the world.

The experience of the last quarter of a century has shown that even the intercourse of traffic, much as it conduces to our prosperity, and which we might expect would cease altogether so soon as it ceased to be mutually advantageous, can be indulged only at the risk of obliging the nation occasionally to assume a belligerent attitude, and of surrendering to the spirit of contention-which seems to govern nations as it does the natural man-a portion of its fruits. The certainty of the return of periods of embarrassment and strife, similar in their origin to that which not long since visited the nation, affords a sufficient reason of itself for securing ourselves in the best manner against the more serious evils of these unavoidable collisions.

But the relation in which this nation stands, a s agreat and flourishing republic, to the monarchies of the transatlantic world, is in fact the hostile array of liberty

against despotism. A separating ocean, while it has hitherto prevented a warfare in which we must necessarily have been one of the parties, has not prevented the conflict of sentiment, nor retarded the march of liberal principles. The governments of Europe contend with each other no longer. The personal ambition of kings; the desire of territorial aggrandizement, of augmenting national wealth; the gratification of national vanity; in short, every motive which would once suffice to deluge the earth with blood, is now effectually restrained under the conviction of impending danger, common and imminent. The obvious interest the coalesced governments have in destroying or poisoning the source whence all those principles adverse to their supremacy have flowed, and in demonstrating, by our disasters, or our ruin, the inefficiency of a popular government, affords good ground for an argument in favor of our assuming a defensive attitude, not only precautionary with reference to our security, but as the most certain prevention to hostile intention.

The progress of illumination abroad, depending, as it must, on the actual state of preparation of the public mind, and on the character of the people-on both of which the several nations of Europe differ more even than in their language— must be irregular and unequal. Hence the contest for freedom will be raging with violence in one quarter, before the people of another shall have fully comprehended the subject of contention, much less have understood its necessity. These partial contests-attended by vacillating success-protracted because they are partial-producing a complication of interests and alliances, diversifying and adding new excitements to our commercial engagements-enlisting on one side all our sympathies-causing us to be regarded by the other with a suspicion even provoking to hostility-can only produce a state of things more embarrassing than any this nation has yet witnessed.

And while a participation, more or less intimate, in the activity of that protracted struggle, cannot be avoided, it becomes us to be prepared, as far as possible, both to avert the calamities and improve the blessings which may result. The subject of our relations with other countries in reference to the cause of war which may grow out of them, is full of interest to the people of this country, and deserves a more profound and detailed examination. With the preceding brief remarks, however, naturally suggesting themselves on approaching the subject of the defence of the country, and bearing in mind that war cannot at all times be avoided, however pacific and forebearing our policy, and that nothing will conduce more to an uninterrupted peace than that state of preparation which exposes no weak point to the hostility, and offers no gratification to the cupidity, of the other nations of the earth, we proceed to consider the means and the mode of the defensive system which it is for the interest of the United States to adopt.

The means of defence for the seaboard of the United States constituting a system may be classed as follows: first, a navy; second, fortification; third, interior communications by land and water; and, fourth, a regular army and well-organized militia.

The navy must be provided with suitable establishments for construction and repair, stations, harbors of rendezvous, and ports of refuge-all secured by fortifications, defended by regular troops and militia, and supplied with men and materials by the lines of intercommunication. Being the only species of offensive force compatible with our political institutions, it will then be prepared to act the great part which its early achievements have promised, and to which its high destiny will lead.

Fortifications must close all important harbors against an enemy, and secure them to our military and commercial marine; second, must deprive an enemy of all strong positions where, protected by naval superiority, he might fix permanent quarters in our territory, maintain himself during the war, and keep the whole frontier in perpetual alarm; third, must cover the great cities from at

tack; fourth, must prevent, as far as practicable, the great avenues of interior navigation from being blockaded at their entrances into the ocean; fifth, must cover the coastwise and interior navigation by closing the harbors and the several inlets from the sea which intersect the lines of communication, and thereby further aid the navy in protecting the navigation of the country; and, sixth, must protect the great naval establishments.

Interior communications will conduct with certainty the necessary supplies of all sorts to the stations, harbors of refuge, and rendezvous, and the establishments for construction and repair for the use both of the fortifications and the navy; will greatly facilitate and expedite the concentration of military force and the transfer of troops from one point to another; insure to these also unfailing supplies of every description, and will preserve unimpaired the interchange of domestic commerce even during periods of the most active external warfare.

The army and militia, together with the marine, constitute the vital principle of the system.

From this sketch it is apparent that our system of defence is composed of elements whose numerous reciprocal relations with each other and with the whole constitute its excellence; one element is scarcely more dependent on another than the whole system is on any one. Withdraw the navy, and the defence becomes merely passive; withdraw interior communications from the system, and the navy must cease in a measure to be active for want of supplies, and the fortifications can offer but a feeble resistance for want of timely reinforcements; withdraw fortifications, and there remains only a scattered and naked navy.

That element in the system of defence to which it is the more immediate duty of the board to direct their attention in this report is the fortification of the coast. It may not, therefore, be unprofitable, while on this part of the subject, to go something more into detail as to the relation of this with the other members of the system; the rather, as the reasons for some conclusions hereafter to be announced by the board will be more apparent.

It is necessary to observe, in the first place, that the relation of fortifications to the navy in a defensive system is that of a sheltering, succoring power, while the relation of the latter to the former is that of an active and powerful auxiliary; and that the latter ceases to be efficient as a member of the system the moment it becomes passive, and should in no case (we allude to the navy proper) be relied on as a substitute for fortifications. This position may be easily established.

If our navy be inferior to that of the enemy, it can afford, of course, unaided by fortifications, but a feeble resistance-single ships being assailed by whole fleets: if it be equal, or superior, having numerous points along an extended frontier to protect, and being unable to concentrate, because ignorant of the selected point of attack, every point must be simultaneously guarded; our separate squadrons may therefore be captured in detail by the concentrated fleet of the attacking power. If we attempt to concentrate under an idea that a favorite object of the enemy is foreseen, he will not fail to push his forces upon the places thus left without protection. This mode of defence is liable to the further objections of being exposed to fatal disasters, although not engaged with an enemy; and of leaving the issue of conflict often to be determined by accident, in spite of all the efforts of courage and skill. If it were attempted to improve upon this mode, by adding temporary batteries and field works, it would be found that, because being weak and inadequate from their nature, the most suitable positions for these works must often be neglected under a necessary condition of the plan that the ships themselves be defended; otherwise they must either take no part in the contest or be destroyed by the superior adversary.

We pass over the great comparative expense of such a mode of defence, rendered clearly apparent by a little reflection, with these brief remarks, viz: that the defensive expenditures by this system will, in the first instance, greatly ex