with which improvements of extended utility make their way into common use, contrasted with the rapid adoption of fashionable changes.--Other causes unfavourable to the adoption of new and useful plans.--Further observations on this subject.--The new system of lighting with coal- gas can never supersede the use of candles and moveable lights.--Gas- light illumination cannot prove injurious to the Greenland fishery-- nor can it diminish the coal trade--must prove beneficial to it.--The price of coal even when it is the highest cannot materially affect the beneficial application of gas-lights.--Striking advantages to be derived from the introduction of gas-lights into manufactories.-- Principal expense which must always attend the gas-light illumination. --Is the dead capital employed for erecting the machinery.--Floating capital is small.--Advice to private individuals with regard to the erection of a gas-light apparatus calculated for their own use.-- Expence which must attend the application of the new system of lighting under different circumstances.--Entire new scheme of illuminating streets, or small towns, with gas-lights; which would save all the main pipes for conveying the gas through the streets as well as the branch pipes which conduct the gas to the lamps.--Manage- ment of the gas-light machinery is extremely simple and easy.--The apparatus not liable to be out of order.--Observations on the safety of the gas-light illumination.--Misapprehension of the public con- cerning it.--Causes that have alarmed the public concerning the application of the new lights.--Gas-lights cannot give rise to those accidents which have so often arisen from the careless snuffing of candles, &c.--Produce no embers or sparks.--Cannot fall, or be dis- turbed without becoming extinguished.--Are the safest of all lights.-- Impossibility of streets or towns lighted with gas to be thrown suddenly into darkness by the fracture of the gas-pipes conveying the gas to the lamps--or by the destruction of one or more of the gas- light machineries employed for preparing the gas.--Illustration showing the absurdity of such mistaken notions.--Curious self-ex- tinguishing lamp, invented by Mr. CLEGG.--His machine which measures and registers in the absence of the observer, the quantity of gas delivered by a pipe communicating with a gas-light _main_.--Leading characters of the new lights.--Objects and views which this art embraces.--It must lessen the consumption of oil.--Occasion a defalcation in the revenue.