618 



PATENTS. 



invention, only a very few came from the United 

 States. The committee of award consisted of 

 Rear-Admiral Seymour, C. B., Capt. Vyvyan, of 

 the royal navy, and Capt. Wyatt. The devices 

 submitted embraced a most extraordinary variety 

 of boats, buoys, kites, balloons, rockets, guns, 

 rafts, mortars, birds and dogs, harpoons, para- 

 chutes, anchors, etc. After long and careful 

 deliberation the judges decided in favor of a 



LIFE-SAVING ROCKET. 



rocket as affording the best means of communica- 

 tion with the shore. Among the 165 rockets 

 that were submitted many were of considerable 

 merit, but the prize was eventually awarded to 

 Messrs. Thompson & Noble, of Southampton. 

 Their invention, as illustrated herewith, is a 

 grapnel that can be readily fitted to the Board 

 of Trade Life-Saving Apparatus Rocket. The 

 grapnel has arms fitted to it, which shut tight 

 against its sides during flight, but on touching 

 the ground they open out and become firmly 

 fixed in the earth when the line is hauled upon. 

 While there seems to be nothing especially origi- 

 nal in this device, it certainly combines effi- 

 ciency, simplicity, portability and economy, and 

 probably represents the best conclusion at which 

 it was possible for the board to arrive. 



Central Screw Propellers. The attention 

 of marine engineers has lately been attracted to 



the possibility of housing screw propellers with- 

 in the midship section of seagoing vessels. The 

 advantage of thus placing the screw is that it is 

 not liable to be thrown out of water when the 

 vessel pitches in a heavy sea, and it is effectually 

 protected against fracture by collision with float- 

 ing substances. The illustrations sufficiently 

 show the general principle. The tunnels in 

 which the screws revolve are open downward, so 

 that the circulation of the 

 water is not perceptibly in- 

 terfered with. Another ad- 

 vantage resulting from this 

 system of construction is 

 that the draft of the vessel 

 may be comparatively light, 

 because, as the midship sec- 

 tion is almost always cer- 

 tain to be submerged, the 

 general draft need not be 

 so deep. One steamer, the 

 " Louvre of Paris," was 

 built and put on service be- 

 tween Paris and London. 

 She made a very good rec- 

 ord for herself for nearly a 

 year, but was unfortunately 

 wrecked, through no fault, 

 however, of her peculiar 

 construction. The year 

 closes with similar vessels 

 in course of construction. 



Jet Propulsion of 

 Ships. This problem con- 

 tinues to attract the at- 

 tention of marine engi- 

 neers who do not appear to be discouraged 

 from the signal failures that have attended the 

 many experiments in this direction. The latest 

 development is the device of Mr. Vogelsang, who 

 uses two or more jets, and in order that they 

 shall act constantly upon undisturbed water he 

 arranges the nozzles through which the jets are 

 discharged in such a way that they continually 

 revolve around an axis. 'This 

 is sufficiently shown in the 

 illustration (see next page), 

 which gives a sectional side 

 elevation at the point of dis- 

 charge. The principle in- 

 volved commends itself to 

 common sense, for it is evi- 

 dent that a single jet must 

 of necessity blow the water 

 away just where solid resist- 



CENTRAL SCREW PRO- 

 PELLER. CROSS- 

 SECTION. 



CENTRAL SCREW PROPELLER. SIDE VIEW. 



