MECHANICS AND USEFUL ARTS. 43 



NEW BOAT LOWERING APPARATUS. 



THE want of a ready means of lowering boats from vessels in dis- 



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tressed circumstances, has been of late years exemplified in numerous 

 cases of the most tragical character. Mr. W. S. Lacon of the East 

 India Company's Service, has recently invented a plan for making the 

 boats attached to a ship quickly available, which seems likely to be 

 entirely successful. Mr. Lacon takes as his principle the well-known 

 axiom in mechanics, that what is gained in power is lost in time ; and 

 although he approves of the method at present in use, as being the 

 best for hoisting up boats ; he (seeing that the hoisting need never be 

 a hurried operation) substitutes two single ropes or chains, which 

 being secured to two broad slings passing round the body of the boat, 

 are then brought inboard on davits, and carried to two concave bar- 

 rels connected together by means of a shaft. The ends of the ropes 

 or chains are secured to the barrels in such a manner that they will 

 support any amount of weight until such time as the boat has reached 

 the water, when they will disconnect and fall away from their attach- 



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ment by their own weight, by which means he prevents the possibility 

 of a ship, in its onward progress through a rough sea, dragging forward 

 a lowered boat sideways, and capsizing or swamping it. By means, 

 then, of a friction strap and pulley round the shaft, one man is ena- 

 bled to regulate the descent of the boat, which will go down by its 

 own weight ; and by means of the parallel action of the two barrels, 

 he lowers both ends uniformly, and insures the boat falling in a proper 

 position on the water. 



Two several trials made at Folkestone on this method of lowering 

 boats, gave great satisfaction to a committee of nautical men. In the 

 first trial, a boat was lowered from the steamer by one man, with sev- 

 eral persons on board, and alighted on the water, abaft of the larboard 

 paddle-box, with the utmost safety and apparent comfort, the tackle 

 being released momentarily by the weight of the boat's descent, the 

 vessel at the time steaming at the rate of 1 2 knots per hour. It was 

 afterwards hoisted up again by two men. At the second trial, the 

 boat was lowered and cleared from the ship by one man, with Mr. 

 Lacou and three men on board, the vessel at the time maintaining 

 full speed. 



PATENT SELF-ACTING SAFETY-PLUG FOR BOATS. 



THE self-acting safety-plug for ships' boats, river barges, lighters, 

 &c., invented by Mr. Lisabe, consists of a hollow brass box, with per- 

 forations at the top and bottom, let into one of the lower planks of a 

 boat or barge. In the interior is a loose ball, with sufficient room for 

 play, so that when the boat is immersed the pressure of the external 

 water urges and retains the ball lightly against an India Rubber seat- 

 ing^ at the top, thereby effectually closing the upper perforations 

 against the admission of water ; while, on the boat being suspended, 

 the ball, by its own gravity, rests upon the bottom of the chamber, 



