As regards the present invention, the accumulation of facts in the numerous certificates, now separately printing, is evidence to those who desire them, that what was anticipated from the correct deductions of theory, has been fully confirmed by a long experience. The writer has adopted, what seemed to him, the easiest and simplest course to bring it before the public. From a great mass of valuable evidence, he has extracted the opinions of the most experienced, to show the rapid destruction of the boilers, the great consumption of fuel, and risk of explosion; obstacles of no little magnitude to the universal substitution of steam for wind power, under the present imperfect system of Steam Navigation: he has explained the theory of the proposed remedy, in language stript of the technicalities of science, to show there is nothing in its principle to render failure probable; and then proved its operation by the evidence of facts. From these every one can draw his own conclusions. Though at the risk of repetition, he will shortly enumerate what it is this invention has been found to effect, requesting the reader will bear in mind an important distinction :— that it is the only mode of preventing incrustation in operation, that involves no alteration of a principle well understood and universally adopted; that, in consequence, it deducts nothing from the proper duty of the engine, which requires no alteration to apply it. It has been found that, by constantly boiling and using the same water, the absence of the usual quantity of air in the condenser enables the engine to work better, producing more revolutions of the wheels; that the pressure of steam, as shown by the gauge, is always greater; that a good vacuum is maintained; that the boilers are kept perfectly clean; that they seldom require cleaning— never chipping; that the danger of explosion for want of Ꭰ water is removed; that a saving of nearly one-third the fuel and tonnage is ensured; that the engine is kept in better order, by the oil and grease circulating through it, and lubricating the valves, these substances being never wasted; that the plan depends upon no complicated machinery for effective operation; that there are no numerous joints, subject to be expanded by steam, and contracted by cold, involving their getting out of order; that the cost is comparatively trifling; and that little time is needed for its application, being merely an appendage; that the pipes are as much protected as the keel of the vessel, and capable of being as securely fixed; that no accident that can happen to them. alone, can delay the vessel a minute, as the Symington and common plan can be used alternately, separately, or combined, by the turning of a cock; and that a few spare pipes will enable any injury to be speedily repaired by the engineer of the vessel. It may also be fairly remarked, that there is no objection that a practical experience of two years has not proved groundless; and that, if there still remain a doubt in the minds of some, such doubt should not, in reason, prevent further inquiry, or be allowed to outweigh so many compensating advantages. For steam boats destined for India, or any of its rivers, impure fresh water being found to be nearly as destructive to the boilers as salt; or for any country where its distance from England removes the facility of repairing them, this invention cannot be too highly estimated; for the saving in fuel, even in the Thames water, is found to be nearly a third. Experience does not yet enable the Patentees to state with accuracy, how many years longer boilers will last, constantly supplied with distilled instead of impure water; but as it is the depositions that are the chief cause of their destruction, if otherwise properly protected, the absence of any must render their duration, without repairs, considerably greater. The difference, as at present known, in the duration of the boilers of the "Dragon" and the other tug, has been noticed at page 26. Mr. Thomas Wilson says, at page 61 of the Report on Steam Vessel Accidents, "As regards boilers, they are frequently worked till wholly worthless, and as thin as paper; and are neither reviewed nor repaired so frequently as they should be. The natural life of an iron boiler may be rated at about four years in the Mersey. Boilers have been taken out of steamers, having their water spaces blocked up with dirt and salt: four or five tons have been removed at a time." The writer has also frequently seen incrustations of an inch thick taken out of the Thames tugs. Without claiming for this invention a degree of importance greater than its merits will justify, yet, looking at what it has done, it may, sometime hence, when prejudice shall be overcome, be considered the greatest improvement in marine engines, since the application of steam to Navigation. It effectually removes its great drawbacks; it has not been found to introduce any disadvantages to counterbalance them. The only proper criterion of every perfect invention is simplicity in the means, efficiency in the end; and these may be applied with much advantage in estimating their importance. Like the separate condenser of Watt-one of that great man's greatest discoveries-it effects by the simplest means the most important results, and does for Steam Navigation what that invention did for the steam engine, saving, when the relative state of machinery at the two periods is taken into account, as great a quantity of fuel. Like that, it is an addition, not an alteration, and is too simple in itself to attract notice; it wants the magnitude and complexity of machinery to excite admiration, until sufficiently estimated by the objects it effects. If the facts stated in the preceding observations have been duly considered, it appears to the writer that little doubt can remain in the mind of every unprejudiced person, that the invention deserves, at least, investigation. If it be thought that the facts themselves have not been ascertained with sufficient accuracy to entitle them to implicit credence, and that trials under other circumstances might have produced different results; all the Patentees ask is, come and make what trials you please, that you may form your own opinion by the evidence of your senses. It is reasonable enough, that every Proprietor of steam vessels should more readily trust to his own experience than to reports, however honest. In this case he has the opportunity of judging for himself, before adopting the invention. This plan permits, as was stated before, the old method to be used at any time after the application of the new; so that, by using the old and new plans alternately, say for three or four hours or a day each, the positive advantages of this invention, and the actual saving in fuel and boilers by its use, can be accurately ascertained. The "Dragon" has done for two years, and is doing every day, on the Thames, what has been stated; and every facility will be afforded for examination, by giving due notice to the Patentees. You can then give the invention a trial upon one of your own vessels, without her detention, and at a comparatively trifling expense. Have everything ready to attach, and when any of your vessels is undergoing repairs, a few days will enable the pipes to be fixed. If the results of the trial on your steamer should be different to what it has been on all others, and contradict a two years' experience, your vessel is not delayed, because the old plan can be instantly resorted to: on her return take off the pipes, and where is the damage or great loss you have sustained? Your vessel |