Incoming ships were boarded in the river, their guns and ammunition dismounted and removed to serve the needs of a vessel bound out on the same tide. The problem of fitting a 12-pounder on a 4.7 emplacement taxed the department's ingenuity and resource, but few ships were held in port for failure of their prompt action. With the near approach to standardization in equipment (a state that came with increased production of merchant-ship arms) the division was able to reorganize on more settled lines. New types of armament were issued to them and there was less adaptation for emplacements to be considered. With every ship fitted, the pressure on their resource was eased, the new ships being constructed to carry guns as a regular part of their equipment. While their activities are now less confused by the new methods, there is no reduction in their employment. Other defensive apparatus has been placed in their hands for issue and control, and their principal port establishments have grown from small temporary offices to large well-manned depots. To the surface guns have been added howitzers, bomb-throwers, and depth-charges for under-water action: smoke-screen fittings and chemicals form a part of their stock in trade: they issue mine-sinking rifles, and even control the supply of our zigzag clocks. The range of their work is constantly being extended. Their duties include inspection to ensure that darkening ship regulations may not fail for want of preparation in port. Makeshift screening at sea is dangerous. Their establishments are at the principal seaports, with branch connections and transport facilities for reaching the smaller harbours. The gun-wharves may not present as splendid a spectacle as the huge store-sheds of our naval bases, but they have at least the busy air of being well occupied, a brisk appearance of having few 'slow-dealing lines' on the shelves. Their permanent staff of armourers and constructional experts are able to undertake all but very major repairs to the ordnance that comes under their charge. By express delivery--heavy motor haulage--they can equip a ship on instant requisition with all that is scheduled for her armament: down to the waste-box and the gun-layer's sea-boots, they can put a complete defensive outfit on the road almost before the clamour of a requesting telephone is stilled. Another of our staff is the officer in charge of our 'Otter' installation, an ingenious contrivance to protect us against the menace of moored mines. For deadly spheres floating on the surface we have a certain measure of defence in exercise of a keen look-out, but our eyes avail us not at all in detecting mines under water moored at the level of our draught. Our 'Otters' may be likened to blind sea-dolphins, trained to protect our flanks, to run silently aside, fend the explosive charges from our course, bite the moorings asunder, and throw the bobbing spheres to the surface.