comparatively few solutions will be found which even approximate to this ideal perfection. But it appears to me that the study of the problems of the liquid and the dissolved states may be much simplified by the recognition (1) that the primary physical properties of liquids and solutions are due to the fact that they are assemblages of molecules endowed with the amount and the kind of kinetic energy which is proper to their temperature; and (2) that as these primary physical properties of the liquid and dissolved states may be masked and interfered with by chemical affinity, they should be studied as far as possible in examples where the influence of this force is either absent or at a minimum.

SUBMARINE NAVIGATION.@

By Sir WILLIAM H. WHITE, K. C. B., LL. D., D. Sc., F. R. S., M. Inst. C. E.,. M. R. I.

Submarine navigation has engaged the attention of inventors and attracted general interest for a very long period. Its practical application to purposes of war was made about one hundred and thirty years ago. The main object of that application was to threaten, or if possible destroy, an enemy's battle ships engaged in blockade by means of under-water attacks, delivered by vessels of small dimensions and cost, which could dive and navigate when submerged. From the first, submarines were admittedly weapons favored by the weaker naval power, and as a consequence their construction found little favor with our naval authorities. Under the conditions which prevailed a century ago in regard to materials of construction, propelling apparatus and explosives, the construction of submarines necessarily proceeded on a limited scale, and the type practically died out of use almost at its birth. Enough had been done, however, to demonstrate its practicability and to make it a favorite field of investigation for inventors, some of whom contemplated wide extensions of submarine navigation. Every naval war gave fresh incentive to these proposals and led to the construction of experimental vessels. This was the case during the Crimean war, when the Admiralty had a submarine vessel secretly built and tried by a special committee, on which, among others, Mr. Scott-Russell and Sir Charles Fox served. Again, during the civil war in America the Confederates constructed a submarine vessel, and used it against the blockading squadron off Charleston. After several abortive attempts and a considerable loss of life they succeeded in destroying the Federal Housatonic, but their submarine, with all its crew, perished in the enterprise.

It is impossible to give even a summarized statement of other efforts made in this direction from 1860 onward to 1880, but one

a Reprinted by permission from author's printed copy.

Read at weekly evening meeting of the Royal Institution of Great Britain, Friday, June 9, 1905, Sir William Crookes, D. Ss., F. R. S., honorary secretary and vice-president, in the chair.

can not leave unnoticed the work done in the United States by Mr. Holland, who devoted himself for a quarter of a century to continuous experiment on submarines and eventually achieved success. The Holland type was first adopted by the United States Navy, and was subsequently accepted by the British Admiralty as the point of departure for our subsequent construction of submarines. In France also successive designs for submarines were prepared by competent naval architects, and a few vessels were built and tried. The Plongeur, of 1860, was a submarine of large size, considerable cost, and well-considered design; but her limited radius of action and comparatively low speed left her for many years without a successor on the French navy list. The high relative standing attained by the French navy as compared with our own, in consequence of the vigorous action of the Emperor Napoleon III in developing steam propulsion and armor protection for seagoing ships, no doubt greatly influenced French policy at that time and delayed development of submarine construction. When conditions were altered in consequence of the Franco-German war of 1870, and the position of the French navy in relation to the British became less favorable, it was natural that the question of submarine construction should assume greater importance in France. In the interval, moreover, great advances had been made in materials of construction and in means of propulsion available for submarines. The extended use of steel and the practical applications of electricity gave to designers greater facilities than existed previously, and public interest in the construction of submarines and small, swift vessels was increased by the writings of the jeune école, who strongly condemned the continued construction of armored" mastodons."

The modern development of submarines for war purposes is chiefly due to French initiative. During the earlier stages of this development progress was extremely slow. The Gymnote was ordered in 1886 and the Gustave Zédé in 1888, and the trials continued over nearly eight years, large sums of money being spent thereon. In 1896 competitive designs for submarines were invited, but no great activity was displayed in this department of construction until the Fashoda incident two years later. Since that time remarkable developments have been made in France, considerable numbers of submarines have been laid down, rival types have been constructed, and many designers have been engaged in the work. Up to the present time about 70 submarines and submersibles have been ordered; in July, 1904, the total number of completed vessels was 28, and at the end of 1907 it is estimated that France will possess 60 completed submarines, with a total displacement of nearly 13,600 tons. The first French submarine of modern type, the Gymnote, was 56 feet long and of 30 tons displacement. The latest

The

types are nearly 150 feet long and of 420 tons displacement. cost of a French submarine designed in 1898 was about £26,000. The estimated cost of the latest and largest vessels is about £70,000. The French have pursued no continuous policy in this development, but have alternated between vessels of comparatively large and others of much smaller displacement. This course had much to recommend it, no doubt, as it brought many accomplished naval architects into competition; but the lack of a continuous and progressive policy has resulted in dissatisfaction and difficulty, and this is frankly acknowledged by French authorities. Two years elapsed after the date when the French resolutely undertook the construction of submarines before the British Admiralty ordered five vessels of the Holland type from Messrs. Vickers, Maxim & Co., who had acquired the concession for the use of the Holland Company's patents. These first vessels in essentials were repetitions of the type which had been tried and officially approved by the authorities of the United States Navy. It was agreed that all improvements made by the Holland Company should be at the service of the British Admiralty through the English concessionaires. In this manner the royal navy at once acquired advantages attaching to the long experience and great skill of Mr. Holland, and with that advantage there was associated the possibility of utilizing their own technical resources and those of Messrs. Vickers, Maxim & Co. For five years a continuous policy has been followed in the development of our submarines, all of which have been constructed at Barrow-in-Furness. There has been a great development in size, speed, and general efficiency, resulting necessarily in correspondingly greater cost per vessel. Information of an official and authoritative character relating to submarines is freely published in France and the United States, but for British submarines corresponding official information is scanty. It has for years been the rule to give in the navy estimates full particulars of dimensions and costs for all other classes of British war ships, but for submarines a policy of secrecy is adopted that is most unreasonable and unnecessary.

From the best sources of information accessible it appears that the growth in size, with a correspondingly increased cost, has been even more rapid here than in France. Our first five submarines are 63 feet in length, 120 tons in displacement, with gasoline engines of 160 horsepower for surface propulsion, giving a speed of 8 to 9 knots. The electric motors for submerged propulsion are estimated to give a speed of about 7 knots. The contract price for each vessel in the United States was about £34,000, and that is about the price paid for our earliest vessels. The latest type of which particulars are available are said to be about 150 feet in length, 300 tons in displacement, · and with gasolene engines of 850 horsepower for surface propulsion, giving a surface speed of 13 knots and a radius of action of 500 miles.

The underwater speed is 9 knots and the radius of action when submerged about 90 miles. No official particulars have been published as to the contract price for these vessels, which is certainly an undesirable course to adopt, seeing that for other and admittedly sufficient reasons these contracts have not been subject to competition as yet. It may be hoped that the Admiralty will reconsider this matter and treat submarines similarly to other vessels.

In French official classification a distinction is made between submarines and submersibles, and this terminology has been the cause of some confusion. Both classes are capable of diving when required and both can make passages at the surface. In this surface condition a considerable portion of the vessel lies above the water surface and constitutes what is technically called a "reserve of buoyancy." In the submersible this reserve of buoyancy and the accompanying freeboard is greater than in the submarine type, and in this respect lies the chief difference between the two types. The submersible has higher freeboard and greater reserve of buoyancy, which secures better seagoing qualities and greater habitability. The deck or platform is situated higher above water, and to it the crew can find access in ordinary weather when making passages and obtain exercise and fresh air. Recent exhaustive trials in France are reported to have established the great superiority of the submersible type when the service contemplated may involve sea passages of considerable length. The French policy, as recently announced, contemplates the construction of submersibles of about 400 tons displacement for such extended services and proposes to restrict the use of submarines to coast and harbor defense, for which vessels of about 100 tons displacement are to be employed. All recent British submarines would be ranked as submersibles according to the French classification, and it is satisfactory to know, as the result of French experiments, that our policy of construction proves to have distinct advantages. In addition to these two types of diving or submarine vessels, the French are once more discussing plans which have been repeatedly put forward and practically applied by M. Goubet, namely, the construction of small portable submarine vessels which could be lifted on board large ships and transported to any desired scene of operations. In the royal navy for many years past it has been the practice to similarly lift and carry second-class torpedo or vedette boats about 20 tons in weight. Lifting appliances for dealing with these heavy boats have been designed and fitted in all our large cruisers and in battle ships, and a few ships have been built as "boat carriers." The first of these special depot ships in the royal navy was the Vulcan, ordered in 1887-88, the design being in essentials that prepared by the writer at Elswick in 1883. The French have also built a special vessel, named the Foudre, which has been adapted for