"Monitors" are novel vessels in our navy, and at present we have only three of them--the _Humber_, _Mersey_, and _Severn_--which were originally built for Brazil, but were acquired from their builders, Vickers, Maxim, & Co., immediately on the outbreak of war. They proved their usefulness by standing close inshore and attacking the flank of the German advance on Nieuport in the fighting between that place and Ostend which took place in the autumn of 1914. Their light draught of water--under 9 feet--enabled them to do this, and rendered them very difficult targets for the German submarines, which, moreover, could not operate in such shoal water. The appearance of the original _Monitor_ in the Civil War in America has already been referred to. The United States Navy had a considerable number of such vessels during and after that campaign. Russia also purchased several of a similar type. But for many years, if we except a few of an improved type which were built for the United States Navy between 1885 and 1895, they fell quite into disuse, except for river work. The Austrians have a small flotilla of such vessels on the Danube, and Brazil has had others for use on the Amazon before the ones we took over were ordered. It is, however, one would imagine, not without the bounds of probability that there may be some return to the shallow-draught "Monitor" type among the battleships of the future, as being less vulnerable to torpedo attack. A battleship design put forward some years ago by a Russian inventor, which he claimed to be nearly torpedo-proof, certainly approximated somewhat to a "Monitor". The three "Monitors" which were added to our own navy as described, are of only 1200 tons displacement apiece. They are 265 feet long, with a beam of 49 feet, and have a speed of 11-1/2 knots only. But it is obvious that speed was of very secondary consideration for the purposes for which they were designed. They have thin armour-plating on their sides, and carry two 6-inch guns in a turret at the bows. Aft are a couple of 4·7-inch howitzers under revolving shields, while half a dozen machine-guns are mounted on their upper works. They are smart-looking little craft, with one funnel and a single military mast with a search-light platform. * * * * *