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PREFACE.

ferent products it furnishe®—the modes of obtainingthem—their properties and applications in the va-rious arts of life.

I have given a description of the apparatus andmachinery by means of which the coal-gas is pre-pared, and the methods employed for distributingand applying it as a substitute for candles and lampsto illuminate houses, streets and manufactories;—I have furnished the data for calculating the ex-pense that must attend the application of this speciesof light under different circumstances, so as to deter-mine the relative cost or value of gas-lights, whencompared with the lights now in use—togetherwith such other practical directions and facts aswill enable the reader to form a proper estimate ofthe gas-light illumination, and to put this art intopractice.

I have stated the leading objects of public andprivate utility to which the new system of lightingmay be successfully applied, candidly pointing outthose in which it cannot be made use of to ad-vantage.

I have detailed the most obvious effects which thediscovery of lighting with coal-gas must inevitablyproduce upon the arts and upon domestic economy ;its primary advantages—its views—its limits, andthe resources it presents to industry and public eco-nomy. I have endeavoured to show how far itsapplication is safe, and in what respect it is entitledto public approbation and national encouragement.