Of these boats the first instalment amounted to a total of eighteen; the most important being the experimental boat _Swift_, which was given a displacement of 1,825 tons, and so might just as well have been designated a fast small cruiser. The horse-power provided was no less than 30,000, the speed 36 knots, though on trials she once reached nearly 39 knots. Armament four 4-inch, two 18-inch tubes. Cost about £280,500. It is interesting to note that in 1885 a precisely similar idea found vent in a _Swift_ (afterwards renamed t.b. 81) of 125 tons against the 40 to 65 tons that was then normal for torpedo boats. It was nine years before anything else of the same size was built. The first standard destroyers of the era were the “Oceans” (often known as “Tribals”). These averaged 880 tons, 33 knot speed with oil fuel only. Between 1906 and 1910 altogether a dozen were built. The armament given to the five first was five 12-pounder, and two 18-inch tubes; in later boats two 4-inch, 25-pounder were substituted for the five 12-pounders. The “coastal destroyers,” which have since lost that name, and are now known as first-class torpedo-boats, were built in groups of twelve for three years; the first batch averaging 225 tons, and later boats about 260 tons. In all the armament is two 12-pounder and three 18-inch torpedo tubes; speed 26 knots. Parsons turbines in all, and oil fuel instead of coal. In 1908–09 there came a revulsion of official feeling against both types, and an attempt to evolve a species of intermediate was made. It was held that the Oceans were exceedingly costly; also somewhat fragile. The new boats, the _Beagle_ class, averaged 900 tons instead of the thousand tons that the latest Oceans were getting to. Armament was reduced to one 4-inch, 25-pounder, and three 12-pounders, with the usual two 18-inch torpedo tubes. Speed was cut down to 27 knots. Oil fuel was done away with, and coal reverted to. The 1909–10 programme provided for 20 destroyers of the _Acorn_ class. These are slightly smaller than the _Beagles_, armed with two 4-inch and two 12-pounders, but with oil again instead of coal only. On account of considerable agitation in Parliament as to the small number of modern British destroyers, the construction of all this class was accelerated by a few months, and with a single exception they were completed in June, 1911. Up till this time considerable latitude had been given to contractors for destroyers. In the 1910–11 programme the _Acheron_ class, an Admiralty design, was given out for fourteen of the boats, which, except that they had two funnels instead of three, closely corresponded with the destroyers of the preceding year. In the other six boats the firms of Thornycroft, Yarrow, and Parsons were given some considerable freedom of design with two boats each, and an increased speed was obtained with all.