d. Steam cylinders. Air pump. Water-tight case containing fan-wheel. Holes in bottom for supplying the wheel in c with water. The principle of this invention is as follows:The hydraulic propeller has a water-wheel inside the vessel. This wheel is enclosed in a metal case, placed under the water-line of the vessel. The wheel is supplied with water from a series of small holes in the bottom of the vessel. The wheel-case has two bent tubes, or nozzles, one at each side of the vessel. The wheel revolves by the power of the steam-engines (which are of the ordinary description of marine-engines), and the water is expelled at each side through these nozzles. The nozzles are bent in such a manner that the issuing water is parallel with the sides of the vessel. There is a contrivance whereby the water from the nozzles may be directed either towards the stern or towards the stem. When flowing towards the stern the vessel will go a-head, and when directed to the stem the vessel will go a-stern. With the water from one nozzle directed towards the stem, and from the other towards the stern, the vessel will go round on its own centre, within its own length. The nozzles, it should be borne in mind, are not placed under, but above, or rather on the water-line. Most people suppose that the propelling force is obtained by the water being forced out of the nozzles against the outside water. But this is not the case; the propelling force is similar to the recoil produced by firing a gun. The advantages which are claimed for this propeller will be seen on reading the following: 1. No loss of power from slip, as in the paddle-wheel or screw, hence greater power is obtained from the same quantity of fuel. 2. The power of the engines is uniform and continuous, producing smooth motion; the vessel is, therefore, free from vibration, and the great wear and tear caused by it. 3. No reaction on the engines from pitching or rolling in a heavy sea, the propelling power remains efficient as in a calm; thus obviating the risk of breaking shafts, paddles, or other parts of the machinery, of so frequent occurrence in other steam ships; and, on a long voyage, this absence of reaction would practically give an increase of speed, or economy of fuel. 4. The vessel is independent of her rudder, and can be turned on her own centre by the propeller alone, without the helm and without steerage way. 5. Can be backed astern or turned instantaneously under the complete control of the commander, officer of the watch, or look-out man on deck, no communication being necessary with the engines, as for this purpose these never require to be slowed, reversed or stopped. 6. The propelling power being situated within the vessel, the risks to paddles or screws from shot, fouling, or other accidents are avoided. 7. This propeller will work effectually whatever the draught of water may be. If the vessel float, she must be propelled and would ascend rivers against any current of less than the usual speed of the vessel, and under circumstances when either paddle or screw would be useless. There not being any wash or swell created, all injury to the banks is avoided; a great consideration on canals and streams with artificially formed banks. 8. In the construction of the hull the lines of a perfect sailing ship can be maintained, these propellers in no way interfering with the efficiency of the vessel as such; and from the facility with which the propelling power can be at once shut off and resumed in any weather without heaving-to, shortening sail, or lessening the speed of the ship, every advantage can be taken of favourable wind of how ever short continuance; this alone creating a great saving of fuel on long sea voyages. 9. Should the vessel be pierced with shot, or spring a leak, the regular supply of water from the canals may be shut off, and the water from the leak taken up instead to supply the centrifugal pump-thus discharging the leak and propelling the vessel at the same time. With a 500 horse-power engine, 1,000 tons of water per minute might be discharged through the nozzles. 10. In construction this propeller differs from the paddle or screw in the following respects:-On the one hand, the paddle-wheels and boxes, sponson beams, and paddle-shaft are dipensed with; on the other, the screw shaft, screwtunnel, and add to these the solid wrought iron double stern-post, so costly in large screw vessels. In lieu of these, the hydraulic propeller requires the turbine-wheel, water-chamber, and nozzles, the cost of constructing which need not exceed that of those parts dispensed with in the paddle or screw. II. From the foregoing it will be readily perceived that the important element of safety is almost completely attained by this invention. It is not too much to say that had the unfortunate London been fitted with this propeller, she could have discharged with a few strokes of her engine all the water which flooded her engine-room. In order to bring this invention before the public, a vessel called the Nautilus has been built, at Blackwall, by the patentee, at the expense of private gentlemen, for the purpose of practically proving the advantages of this mode of propulsion. A trial-trip was made on Saturday, March 24, 1866, when the superiority of this invention was fully proved. This vessel, fitted with engines of 20-horse power, was able, with a less expenditure of steam, to distance a paddle-boat of 24-horse power. This vessel has made many trips on the river, and very many persons, scientific, practical builders, and others, have witnessed her performance. One and all, however, expressed their approbation, and many their astonishment at the results. On the 8th of April a trial trip of a more formal character was made, on which occasion one of the best of the up-river paddleboats was hired for the purpose of racing with, and fairly testing the merits of, the hydraulic, as compared with the paddle-wheel propeller. The Volunteer, the vessel referred to, was a smaller vessel, of much finer lines for sailing, and of greater horse-power. The Nautilus had, moreover, over a hundred people on board, while the Volunteer had merely her own officer and one or two gentlemen, to see that she did her very best in the race. Yet the Nautilus, though using less steam, had no difficulty in beating her, of which fact every person on board was satisfied, and the proof seemed complete that the hydraulic, with same power, will beat the paddle, leaving the many other advantages peculiar to the former to the good. With this practical proof of the utility of this invention, we may fairly prognosticate a great and glorious future for the hydraulic propeller, and a few scientific gentlemen can obtain permission to inspect the vessel by applying to the inventor. Additional trials will be sufficient to place this project among the great successes of the age we live in. The Waterwitch, launched in June, will not be completed and ready for trial until the beginning of October. F. J. D. SALMON CULTURE IN AUSTRALIA. CCOUNTS recently received from Hobart town and other places in the colonies of Australia, where the propagation of salmon is being carried on, assure us of the very great success which has attended the efforts of Messrs. Youl, Wilson, Ramsbottom and other Australian gentlemen, now in England to naturalize salmon into Australia. The following letter from Mr. W. Ramsbottom, superintendent of the salmon breeding establishment at New Norfolk, says: "On my opening some of the first ova boxes at Melbourne, I had very grave thoughts about our chances of success, as I was sure upwards of 70 per cent. were dead, and I had then before me our voyage to Hobart town, with the dangers connected with reshipping—a work to be repeated three times-and then the boxes had to be carried for four miles on men's shoulders to the ponds. However, when I opened one or two boxes of ova which were taken from the bottom of the ice-house, I assure you words cannot express my feeling on seeing certainly upwards of 70 per cent of healthy The difference was really astonishing between the two lots of ova, those packed on top of the ice and those at the bottom. ova. "After we arrived at the ponds and the deposition of the ova completed, I could with great confidence say we had at least from 40 to 50 per cent of healthy ova; we then cleared away the moss, &c., after which we began our most tiresome work of picking out all the dead ova, which took us something over six days; since then I have been able to count out all that have died during each 24 hours. The deaths have been numerous, but not so many as might have been expected when we take into consideration the age of the ova, or how long ago it is since the ova were taken from the parent fish-now 122 days. But with all I have every confidence that we shall hatch out a great number of young salmon this time. "The hatching, of course, has commenced and this morning I can count 98 infants and looking well, and before the English mail leaves Australia, I have no doubt but that there will be upwards of 1,000." This fully proves that the measures which were taken as regards the packing of the salmon ova were dictated only after many experiments and great anxiety, and the successful issue of them can only be a source of congratulation to all initiators of a fresh inhabitant into a new country, more especially to those who are engaged as Messrs. F. Buckland, Youl, Wilson in England and Australia, and in America by Mr. Stephen H. Ainsworth, whose remarks as to feeding we herewith append from a back number of this journal: "The most difficult period in growing trout artificially is about the time they commence feeding. This period is from forty to sixty days after hatching, according to the temperature of the water, At this time a large proportion of them are very weak, and are entirely unable to stand the least current, and consequently are carried with the current through the whole length of the hatching-box against the screen (if one) at the lower end of the box, and are soon suffocated and die. To obviate this put a tank 12 ft. square at the lower end of the hatching-box, so that the water will run into it, with a gentle current, carrying the weak trout with it into the tank, where they can rest in still water from 2 to 3 inches deep. In this way they will soon recover and come into the very slight current to look for food, and, as they grow stronger, run up the hatching-box again. By this arrangement I have decreased the mortality so that I lose but a very small per centage compared to what I did before." |