One thing that this war has shown us is that the Germans have not got a monopoly in the manufacture of first-class optical lenses. In 1914 the German periscope was a lot better than ours; in 1915 we put out contracts for periscopes to new firms in this country; in 1916 our new periscopes equalled those of the enemy; in 1918 our latest periscopes were the best in the world. This advance was accomplished by our firms in face of two handicaps--one, that our periscopes ordered were some seven feet longer than the enemy's; the other, that ours were to be practically vibrationless. The results gained have broken the bubble of reputation previously raised by the Jena glass factories. In the Diesel oil-engine the Germans probably lead us--in steam turbines we lead them. In general submarine design and practice we are a long way ahead, while in certain minor details they give us points to copy. Among a mass of clumsy fittings in their boats (fittings which had long ago been eliminated or simplified with us) one finds small labour-saving "gadgets" installed which we have either not thought of, or have neglected to supply. A typically German piece of thoroughness is to be seen--one specimen on Zeebrugge Mole, the other at Wilhelmshaven. This is a raised platform carrying a gun on top; the platform works on eccentric bearings which are able, through the use of a separate motor, to roll or pitch the gun to a variable amount while the submarine gunlayer under training endeavours to carry out practice at a target towed past him out at sea. It is also reported that this arrangement is sometimes used to cure submarine sailors of excessive sea-sickness: this is probably true, as an hour's stay on the rocking platform would cure the most hardened case. As our boats did not use the gun much, such a contrivance was not needed; but in any case such shore training, as opposed to practice at sea, is against the usual habit of our Navy. Which method is right--well, there's something to be said for both sides.