The fortification of the coaling stations for the British empire is still proceeding on a scale which, in some cases, cannot easily be reconciled with the principles laid down by the president of the cabinet committee of defence. At the Guildhall, London, on the 3rd of December 1896, the duke of Devonshire stated that “The maintenance of sea supremacy has been assumed as the basis of the system of imperial defence against attack from over the sea. This is the determining factor in fixing the whole defensive policy of the empire.” It was, however, he added, necessary to provide against “the predatory raids of cruisers”; but “it is in the highest degree improbable that this raiding attack would be made by more than a few ships, nor could it be of any permanent effect unless troops were landed.” This is an unexceptionable statement of the requirements of passive defence in the case of the coaling stations of the British empire. Their protection must depend primarily on the navy. Their immobile armaments are needed to ward off a raiding attack, and a few effective guns, well mounted, manned by well-trained men, and kept in full readiness, will amply suffice.
If the command of the sea is lost, large expeditionary forces can be brought to bear upon coaling stations, and their security will thus depend upon their mobile garrisons, not upon their passive defences. In any case, where coal is stored on shore, it cannot be destroyed by the fire of a ship, and it can only be appropriated by landing men. A small force, well armed and well handled, can effectually prevent a raid of this nature without any assistance from heavy guns. In war, the possession of secure coal stores in distant ports may be a great advantage, but it will rarely suffice for the needs of a fleet engaged in offensive operations, and requiring to be accompanied or met at prearranged rendezvous by colliers from which coal can be transferred in any sheltered Modern conditions. waters. In the British naval manœuvres of 1892, Admiral Sir Michael Seymour succeeded in coaling his squadron at sea, and by the aid of mechanical appliances this is frequently possible. In the Spanish-American War of 1898 some coaling was thus accomplished; but Guantanamo Bay served the purpose of a coaling station during the operations against Santiago. Watering at sea was usually carried out by means of casks in sailing days, and must have been almost as difficult as coaling. As, however, it is certainty of coaling in a given time that is of primary importance, the utilization of sheltered waters as improvised coaling stations is sure to be a marked feature of future naval wars. Although coaling stations are now eagerly sought for by all powers which cherish naval ambitions, the annexation of the Hawaiian Islands by the United States being a case in point, it is probable that they will play a somewhat less important part than has been assumed. A fleet which is able to assert and to maintain the command of the sea, will not find great difficulty in its coal supply. Moreover, the increased coal endurance of ships of war tends to make their necessary replenishment less frequent. On the other hand, the modern warship, being entirely dependent upon a mass of complex machinery, requires the assistance of workshops to maintain her continuous efficiency, and unless docked at intervals suffers a material reduction of speed. Prolonged operations in waters far distant from home bases will therefore be greatly facilitated in the case of the Power which possesses local docks and means of executing repairs. Injuries received in action, which might otherwise disable a ship during a campaign, may Secondary bases. thus be remedied. During the hostilities between France and China in 1884, the French ship “La Galissonnière” was struck by a shell from one of the Min forts, which, though failing to burst, inflicted serious damage. As, by a technical fiction, a state of war was not considered to exist, the “La Galissonnière” was repaired at Hong-Kong and enabled again to take the sea. Local stores of reserve ammunition and of spare armaments confer evident advantages. Thus, independently of the question of coal supply, modern fleets employed at great distances from their bases require the assistance of ports furnished with special resources, and a power like Japan with well-equipped naval bases in the China Sea, and possessing large sources of coal, occupies, for that reason, a favoured position in regard to naval operations in the Far East. As the term “coaling station” refers only to a naval need which can often be satisfied without a visit to any port, it appears less suitable to modern conditions than “secondary base.” Secondary bases, or coaling stations, when associated with a powerful mobile navy, are sources of maritime strength in proportion to the services they can render, and to their convenience of geographical position. In the hands of an inferior naval power, they may be used, as was Mauritius in 1809-1810, as points from which to carry on operations against commerce; but unless situated near to trade routes, which must be followed in war, they are probably less useful for this purpose than in sailing days, since convoys can now be more effectively protected, and steamers have considerable latitude of courses. Isolated ports dependent on sea-borne resources, and without strong bodies of organized fighting men at their backs are now, as always, hostages offered to the power which obtains command of the sea.
(G. S. C.)
COALITION (Lat. coalitio, the verbal substantive of coalescere, to grow together), a combination of bodies or parts into one body or whole. The word is used, especially in a political sense, of an alliance or temporary union for joint action of various powers or states, such as the coalition of the European powers against France, during the wars of the French Revolution; and also of the union in a single government of distinct parties or members of distinct parties. Of the various coalition ministries in English history, those of Fox and North in 1782, of the Whigs and the Peelites, under Lord Aberdeen in 1852-1853, and of the Liberal Unionists and Conservatives in Lord Salisbury’s third ministry in 1895, may be instanced.
COAL-TAR, the black, viscous, sometimes semi-solid, fluid of peculiar smell, which is condensed together with aqueous “gas liquor” when the volatile products of the destructive distillation of coal are cooled down. It is also called “gas-tar,” because it was formerly exclusively, and even now is mostly, obtained as a by-product in the manufacture of coal-gas, but the tar obtained from the modern coke-ovens, although not entirely identical with gas-tar, resembles it to such an extent that it is worked up with the latter, without making any distinction in practice between the two kinds. Some descriptions of gas-tar indeed differ very much more than coke-oven tar from pure coal-tar, viz. those which are formed when bituminous shale or other materials, considerably deviating in their nature from coal, are mixed with the latter for the purpose of obtaining gas of higher illuminating power.
It may be generally said that for the purpose of tar-distillers the tar is all the more valuable the less other materials than real coal have been used by the gas-maker. All these materials—bog-head shale, bituminous lignite and so forth—by destructive distillation yield more or less paraffinoid oils, which render the purification of the benzols very difficult and sometimes nearly impossible for the purposes of the manufacturer of coal-tar colours.
Neither too high nor too low a temperature should have been observed in gas-making in order to obtain a good quality of tar. Since in recent times most gas retorts have been provided with heating arrangements based on the production of gaseous fuel from coke, which produce higher temperatures than direct firing and have proved a great economy in the process of gas-making itself, the tar has become of decidedly inferior quality for the purposes of the tar-distillers, and in particular yields much less benzol than formerly.
Entirely different from gas-tar is the tar obtained as a by-product from those (Scottish) blast furnaces which are worked with splint-coal. This tar contains very little aromatic hydrocarbons, and the phenols are of quite a different character from those obtained in the working of gas-tar. The same holds good of oil-gas tars and similar substances. These should not be worked up like gas-tars.