Chapter VII.

While I should be far from recommending torpedo warfare as an important means of defence, and would not be disposed to allow it to form a link or essential part of the general system of American defences, I should advocate the use of such means in superaddition to those of earthwork shore batteries and land defences as an extra precaution, which would insure the success of the defence of the "channel approaches" to our ports, even under the most unfavorable circumstances and accidents.

It is well known that, to prevent the danger of vessels running the gauntlet of shore batteries, in the hope of penetrating to the harbor beyond, without first silencing the forts, a strong boom of heavy logs, chained end to end, is generally stretched across the channel to be defended against the passage of hostile ships. Such boom is strengthened sometimes by anchors at intervals, and sometimes by piles, or by sunken vessels. Sometimes that are made entirely of massive links of iron, floated by being attached to large logs. Booms cannot, however, be made so strong as to resist the shock of a large ship. They are sometimes broken or separated by the smaller vessels of a squadron, and sometimes by the violence of the waves. They cannot be counted upon as an impassable barrier to the exertions of a fleet, even when stretched across the channel under the fire of shore batteries.

As a supplement to this auxiliary defence of a channel, and to supply its place, if broken through, and in the event of the shore batteries being silenced to present a second formidable obstacle to his ships, the following described system of torpedoes may be useful. It will be observed that these have this great advantage over the boom, (which, however strong, is a negative or passive obstruction,) that they are, above all other obstructions, dangerous as well as difficult; so much so, that it may safely be asserted that, by properly combining them with the shore batteries, so as to be capable of being fired from thence, the enemy would be compelled to take possession of such shore batteries, and gain access to the firing stations, before he would dare to risk the passage of the torpedo-obstructed channel.

II.

It might be thought that the extraordinary properties of such obstructions warrant a reliance upon them as a primary means of channel defence, and that they are here assigned too low a rank in the general system proposed. To such suggestions, I answer that the case must be regarded as it stands. We have spent many millions of dollars upon masonry fortifications. In some cases they are nearly adequate in themselves for channel defence. At New York, the point mainly under consideration, the works already built will fully answer such purpose, provided they receive a certain reinforcement of earthen shore batteries. It would, not, therefore,be worth while to propose any plan by which torpedoes might, if they were capable, be utilized

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