Indeed, in all cases, where flames for producing light are placed near to each other, it is always beneficial to preserve the heat of the flame as much as possible. One of the most simple methods of doing this, is no doubt, the placing of the several flames together, and as near as possible to each other without touching, in order that they may mutually cover and defend each other against the powerful cooling influence of the surrounding cold bodies. This principle is now employed in the Liverpool lamp, which acts by several flat or ribband wicks placed in the form of a cylinder. The power of illumination of this lamp is superior in effect and more economical than any other lamp in use--and as flame is perfectly transparent to the light of another flame which passes through it, there is no danger of loss of light on account of the flames covering each other. PART II. GAS-LIGHT. PRELIMINARY OBSERVATION. A new art of procuring artificial light, which consists in burning the gazeous fluid obtained by distillation from common pit-coal, has of late engaged the attention of the public, under the name of _gas-light_. The encouragement that has been given for some years past by the legislature to this system of lighting, has induced certain individuals to apply the coal-gas light for the illumination of streets, houses, roads, and public edifices. And it is sufficiently known that a company has been incorporated by charter under the name of the “_Gas Light and Coke Company_,” to apply this new art of procuring light, by way of experiment, on a large scale, in lighting the streets of the metropolis.[10] [10] An Act for granting certain powers and authorities to a company to be incorporated by charter, called the “Gas Light and Coke Company,” for making inflammable air for the lighting of the streets of the metropolis, &c.--Session 1810, 50th Geo. III. The power and authorities granted to this corporate body are very restricted and moderate. The individuals composing it have no exclusive privilege; their charter does not prevent other persons from entering into competition with them. Their operations are confined to the metropolis where they are bound to furnish not only a stronger and better light to such streets and parishes as chuse to be lighted with gas, but also at a cheaper price than shall be paid for lighting the said streets with oil in the usual manner. The corporation is not permitted to traffic in machinery for manufacturing or conveying the gas into private houses, their capital or joint stock is limited to 200,000_l._ and His Majesty has the power of declaring the gas-light charter void, if the company fail to fulfil the terms of it. THEORY OF THE COMBUSTION OF COAL IN ELUCIDATION OF THE NATURE AND PRODUCTION OF GAS LIGHT.