THE 



AMUAI OF SCIENTIFIC DISCOYERY. 



MECHANICS AND USEFUL ARTS. 



THE GREAT EASTERN. 



THE Great Eastern, steamship, the principle of whose construction and 

 history has been given in previous numbers of the Annual of Scientific Dis- 

 covery, has, during the past year, been fully completed. The following de- 

 tailed descriptions of her machinery and fittings are necessary to complete 

 the record : 



The motive agents of the Great Eastern are paddle-wheels and a screw. 



Paddle - Wheels. The paddle-wheels are fifty-six feet in diameter, and 

 their weight is one hundred and eighty-five tons. Provision has been made, 

 when the ship is deeply laden, for reefing that is, drawing in the floats - 

 ten feet, although, as every float would have to be treated separately, it is 

 not likely it will be made much use of. The floats are thirteen feet b}* three 

 feet, and thirty in number to each wheel. The wheels are connected to the 

 engines by friction-straps, so that they can be disconnected at any time, if 

 it should be necessary to use the screw by itself. The forgings connected 

 with the paddle-wheels are of the following Aveights and dimensions : Two 

 paddle-cranks, each seven feet between the centres, and weighing, when 

 forged, eleven and a half tons ; when finished, ready for putting on to the 

 shafts, seven tons four hundred. The paddle-shafts, each thirty-eight feet 

 long, and weighing thirty tons. We have next the large, intermediate 

 crank-shaft; its depth of throw is five feet one inch; thickness, two feet 

 nine inches; greatest diameter, two feet seven inches; length over all, 

 twenty-one and a half feet; weight, thirty-one tons. The two friction- 

 straps, for disconnecting paddles, are each ten feet inside diameter, and 

 fifteen inches thick; and the weight of each is nine tons twelve hundred 

 weight. 



