estimated. Tubular boilers at once became universal in all ships built for the service, and to this day nobody would dream of applying any but oscillating engines to the driving of paddles. The 'Black Eagle' had side-
ENGINES OF THE ‘BLACK EAGLE.’
lever engines in the first instance, but these were removed and replaced by oscillating ones by Messrs Penn.
In 1846 was commissioned, by Captain William Ramsay, the 'Terrible,' the most powerful steam fighting ship in the world at that date. She was of 1847 tons burthen, carried an armament of twenty-one guns of various calibres, and was fitted with double-cylinder direct-acting engines of 800 horse power by Messrs Maudslay. And here it may be well to digress for a moment to point out to the reader that when speaking of the horse power of the earlier engines 'nominal’
