So little is known of the possibilities of submarine vessels of the second type that it seems necessary for me to devote some time to describing their possibilities and my experience in their construction. In 1905, while living in Berlin, Germany, I prepared plans for a mine-laying submarine for submission to the Russian Government, a general description of which was published in 1906. This submarine was designed to carry thirty-six of the regulation naval mines, which could readily be placed in a desired locality while the submarine was entirely submerged. A vessel of this type might be useful for either offensive or defensive purposes. Where used for offensive purposes the mine-laying submarine could readily, with comparatively little danger to herself, plant mines off entrances to the enemy's harbor. Equipped with the "mine-evading" guards, they might even work their way into an enemy's harbor and plant mines under a vessel at anchor, or destroy shipping lying tied up at the docks. For defensive purposes a mine-laying submarine would be of great value, as it could readily plant mines, even under the guns of a powerful fleet, to protect its own entrances and harbors. The submarine _Protector_, built in 1901 and 1902 at Bridgeport, Connecticut, was fitted with a diving compartment which corresponds to the mine-laying compartment of the 1905 design above referred to. The importance of a mine-laying submarine for the defence of the country was first officially called to the attention of the American people by a board of officers appointed by ex-President Taft, then Secretary of War, as early as January, 1903. This board of officers consisted of General Arthur Murray, late chief of Coast Artillery Corps (then Major); Captain Charles J. Bailey, and Captain Charles F. Parker, of the Artillery Corps. The following is a copy of their recommendations for this type of vessel for the defence of our coast: