The Goubet class are of iron, sixteen feet long, three feet wide, and about six feet deep. The motive power is a Siemens motor driven by storage batteries. Fifty of these boats were purchased by the Russian government. They have no rudder, but a universal joint in the screw shaft permits of the screw being moved through an arc of ninety degrees. The torpedo is carried outside the boat, secured by a catch worked from inside. On arriving under the enemy, the torpedo is released, and striking the ship's bottom, is held there by spikes. The boat then withdraws, unreeling a connecting wire; and when at a safe distance, fires. The absence of a rudder, however, causes erratic steering, and the spikes with which the torpedo is fitted might fail to stick in steel-bottomed ships. Submarine boats cannot be driven under water at a speed exceeding six knots. If driven beyond, they are inclined to dive, and in deep water, before the corrective forces against a dive have had time to act, might reach a depth where the pressure would drive in the sides or compress them to a sufficient extent to seriously reduce the displacement. In shallow water, the boat might be driven on to the bottom, and if it be clay, held there, an accident attended with fatal consequences in the case of one boat. It is also difficult to direct the course of a submarine boat; and it is doubtful whether the advantage of not being seen counteracts the disadvantage of not being able to see. According to Mr Nordenfelt in a lecture on Submarine Boats, 'The mirror of the surface throws a strong light into the boat; you cannot see forward at all, and you cannot see far astern; it is as black as ink outside; you can only see a sort of segment.' This means that you cannot safely advance at a great speed under water. It is impossible to think of a submarine boat as a boat that actually manoeuvres and does its work under water. The boat should run awash, and you can then see where you are. When we consider, then, that a boat totally submerged cannot be driven over six knots, and cannot be properly directed; when we consider the speeds of seventeen and eighteen knots attained by modern battleships, we arrive at the conclusion that boats totally submerged are useless against modern battleships in motion. Running awash, they could be tackled by torpedo catchers and torpedo boats. [Illustration] CHAPTER VII. EVOLUTION OF THE CYCLE. In praise of Cycling--Number of Cycles in Use--Medical Opinions-- Pioneers in the Invention--James Starley--Cycling Tours.