In the old days the frigate was the cruiser, she was unarmoured, that is, her sides were so much thinner than those of the battleship that she was not able to fight in the line of battle, but the weak gun fire of those days permitted close scouting by such unprotected vessels, she could approach a battleship squadron very closely without fear of damage, she could sail round a fleet and count their numbers without danger to herself, unless chased off by other frigates, she was a scout and a commerce destroyer. Similarly with present day armoured cruisers, they can force their way up to within sight of a fleet, and observe them, unless chased off by other armoured cruisers, but to do this they have to be given a certain amount of protective armour. The range of eyesight has remained constant, that of gunfire has increased. Speed is a necessity to ensure safety, armour protection to ensure vision. It is evident, from the above considerations, that the functions of the frigate have devolved on the armoured cruiser to a greater extent than have the functions of the line of battleship devolved on the modern battleship. But how about the unarmoured cruisers and those of low speed? With loss of protection a cruiser loses her power of reasonable approach for observation purposes, and if to this be added a loss of reasonable speed her safety is gone. Cruisers without high speed and protection are entirely and absolutely useless. Every vessel that has not high scouting speed, or the highest defensive and offensive powers, _is useless for fighting purposes_. This is true of every class of vessel between the first class armoured cruiser and the fast torpedo vessel. NUCLEUS CREWS. It is impossible to exaggerate the vital importance to the nation of having all the reserve ships absolutely ready for instant war. Our reserve ships, as they are now, are not, and cannot be made really efficient fighting units under several months of commission. There is no doubt that great strides towards rapid mobilisation have been made of late years, but merely to hustle a complement of the required ratings into a ship, is not to make her a really efficient fighting machine. _The keystone of our preparedness for war has now to be inserted, namely, the provision of efficient nucleus crews._ _This can be done to-morrow._ A nucleus crew should consist of approximately two-fifths of her engine-room complement, the whole of her turret crews, gun layers and sight-setters for all guns, all important special ratings, and two-fifths of her normal crew, her captain, and all important officers. The ship can proceed half-yearly, or quarterly, as may be required, to sea with her fighting ship’s company to carry out firing exercises, or to work under the Admiral or Commodore who will command her and her consorts in war, and be as nearly perfectly efficient as any ship, not always at sea, can be.