The paravane, an English invention, proved of great value in protecting ships from mines. Its "wings," spread out in the water, picked up mines; and its wires bore them away from the ships, where they could be exploded without danger to the vessel.
Mines played a big part in naval warfare. The Germans sowed the seas with them, and if the Allied mine-sweepers had not been so energetic and skillful, they might have been as destructive to shipping as the U-boats were. Our Bureau of Ordnance led in mine development, and the new mine, called "Mark VI," which it produced in 1917, was decidedly superior to any of its predecessors, and was the type used by us in the North Sea Barrage.
Better guns for aeroplanes was a vital need. Machine-guns were made more effective; but for anti-submarine warfare there was needed something of larger caliber, with sufficient power to penetrate the hull plating of the U-boat. An aeroplane "cannon," the Davis non-recoil gun, was produced.
A 37-millimeter automatic cannon was being developed, as well as a three-inch gun for the larger type of dirigibles. Aerial bombs were improved and enlarged until they reached a weight of 550 pounds, with 190 pounds of explosive, the largest type being 15 inches in diameter and over 62 inches in height. Various experiments were made in launching torpedoes from planes, and torpedo planes were designed to accompany the fleet.
Night firing, naval experts realized, could be made much more effective by some method of illuminating the area around enemy ships without disclosing the position of our own. This was solved by "star" shells. Fired at long distances and exploding high in the air, these shells light up a considerable area, bringing out in bold relief the vessels beneath.
Range-finding and fire-control devices were improved, increasing the efficiency of large and medium caliber guns. "Smoke boxes" were manufactured by the thousand and placed aboard merchant as well as naval vessels, so that in case of attack they could make smoke screens.
So many new devices were developed that it would take volumes to tell of them all. Though thousands of the suggestions made were impracticable, not a few were of decided value, and the result as a whole was fresh proof of the never-failing inventiveness and genius of Americans.
When the Navy Department, in 1915, was planning its large program of construction, and seeking for new weapons and new strategy to combat the submarine, I was convinced that it would be of great assistance if civilian scientists and inventors could be induced to give the Navy the benefit of their experience and ability. This resulted in the creation of the Naval Consulting Board. On July 7, I wrote Mr. Edison inviting him to become the head of the Board, saying:
One of the imperative needs of the Navy, in my judgment, is machinery and facilities for utilizing the natural inventive genius of Americans to meet the new conditions of warfare as shown abroad, and it is my intention, if a practical way can be worked out, as I think it can be, to establish, at the earliest moment, a department of invention and development to which all ideas and suggestions, either from the service or from civilian inventors, can be referred for determination as to whether they contain practical suggestions for us to take up and perfect.