[24] I am informed by Mr. CLEGG, the engineer of the Chartered Gas-Light Company, under whose direction the new system of lighting is carried on, that the total length of pipe laid down, as mains, in the streets of London amounts already to nearly 15 miles. In the Eastern part of London, the same Company is engaged to lay their pipes in the principal parts of Whitechapel, Spitalfields, St. Luke’s, and the adjoining neighbourhood. One part of the city of London, extending from Temple-bar to the West end of Cheapside; from Newgate-street to Holborn Bars, together with the intervening streets, is also provided with pipes laid down by another gas-light association, who have opened a new Establishment in Water-lane, Fleet-street, but are unconnected with the Chartered Company. A third company is projected in Southwark, and a fourth in the Eastern district of London, creating by a rivalry of interest, that laudable competition which always proves beneficial to the public at large, and which cannot fail to accelerate the progress of this new art of procuring light. The Church of St. John the Evangelist in this metropolis has been illuminated with gas-lights for upwards of two years: the lights employed in this edifice is equal to 360 tallow candles eight to the pound. The avenues to the House of Lords and House of Commons, Westminster-hall, Westminster-bridge; the house and offices of the Speaker of the House of Commons, the Mansion-house, and many other places, deserve to be named, as having already adopted this species of illumination. Another advantageous application of the gas-light must be the supplying of light-houses. From the splendour and distinguishing forms which the gas-light flame is capable of assuming, no light is better calculated for signal-lights than this. By means of one single furnace as much gas might readily be procured as would furnish a flame of sufficient intensity, during the longest winter night, exceeding in brilliancy or intensity of light any light-house in Britain or elsewhere. If every light-house round this island were possessed of a gas-light furnace, one-half part of the enormous expence which they at present require would furnish a much more brilliant light. The cheapness of this light and its efficacy for the purpose, would soon multiply the number of light-houses, and thus most essentially contribute to the security of navigation on our coast. The gas may be made to issue from tubes by long narrow slips, and a surface of flame produced of any given dimensions, and free from all smoke that would obscure the reflectors.