MECHANICS AND USEFUL ARTS. 81 



plate and the bridge, and is thus so intensely heated as continuously 

 to produce the entire combustion of the gaseous products of the fuel, 

 and to prevent the ordinary formation of smoke. 



Smokeless Chimneys. Major Browne, of London, has recently pa- 

 tented an apparatus for preventing the egress of smoke from the tops 

 of chimneys. The invention is applicable to old chimney shafts, or 

 in the construction of new ones the height might be very considerably 

 reduced. The top of the chimney is closed in, and at about half-way 

 up in those of present construction an opening is made in the side as 

 large as the structure will allow. Outside of this an iron box is firm- 

 ly secured, in which is a foliated revolving cylinder, its axis placed 

 horizontally, having a grooved pulley geared to the motive power by 

 which it is set in motion. The leaves of this cylinder are curved 

 downwards in the direction of its rotation, to facilitate collecting and 

 carrying downwards the solid particles of carbon, and the denser va- 

 pors into a tank beneath, containing water, and in which it partially 

 revolves. This tank has two openings, one to insert fresh water, the 

 other to withdraw the collected matters. When the smoke reaches 

 the opening it comes within the immediate action of the draught 

 caused by the rapid revolution of the vanes, and is quickly condensed 

 in the cold water trough. 



A new law for the abolition of the smoke nuisance in London went 

 into operation in August, 1853. 



There are eight sections in the law, and it enacts that from and after 

 the 1st of August, furnaces in the metropolis shall consume their own 

 smoke, under penalties described. The act extends to any mill, factory, 

 printing-house, dye-house, iron foundry, glass-house, distillery, brew- 

 house, sugar refinery, bakehouse, gasworks, waterworks, or other 

 buildings used for the purpose of trade or manufactures, within the 

 metropolis. From the same day steam-vessels on the Thames above 

 London bridge are to consume their own smoke, under penalties to be 

 recovered in a summary manner before a magistrate. The words, 

 " consume or burn the smoke." are not to be held in all cases to mean, 

 "to consume or burn all the smoke;" and the justice before whom 

 any persons shall be summoned may remit the penalties if they are of 

 opinion that such person has so constructed or altered his furnace as 

 to consume or burn, as far as possible, all the smoke arising from it, 

 and has carefully attended to the same, and consumed or burned the 

 smoke arising from the furnace. Constables may be empowered to 

 enter and inspect furnaces and steam engines. 



IMPROVEMENTS IN CRUSHING AND PREPARING ORES. 



Machine for Separating Ores. An important apparatus for separa- 

 ting ores and other substances of different specific gravities and of 

 different magnitudes into their constituent parts, has been invented 

 by Victor Simon, of Nerviers, Belgium ; the inventor, Mr. S., accom- 

 plishes the desired object, by passing a current of air through a long 

 trunk or tube placed horizontally, or nearly so, with a series of re- 



