Transcriber’s notes Italics in the original work are transcribed between _underscores_; small-capitals have been transcribed as all capitals. More transcriber’s notes and a list of corrections made may be found at the end of this text. [Illustration: FIG. 1] A PRACTICAL TREATISE ON GAS-LIGHT; EXHIBITING A SUMMARY DESCRIPTION OF THE APPARATUS AND MACHINERY BEST CALCULATED FOR ILLUMINATING STREETS, HOUSES, AND MANUFACTORIES, WITH CARBURETTED HYDROGEN, OR COAL-GAS, WITH REMARKS ON THE UTILITY, SAFETY, AND GENERAL NATURE OF THIS NEW BRANCH OF CIVIL ECONOMY. BY FREDRICK ACCUM, _OPERATIVE CHEMIST_, LECTURER ON PRACTICAL CHEMISTRY, ON MINERALOGY, AND ON CHEMISTRY APPLIED TO THE ARTS AND MANUFACTURES; MEMBER OF THE ROYAL IRISH ACADEMY, FELLOW OF THE LINNÆN SOCIETY, MEMBER OF THE ROYAL ACADEMY OF SCIENCES OF BERLIN, &c. &c. WITH SEVEN COLOURED PLATES. London: PRINTED BY G. HAYDEN, BRYDGES-STREET, COVENT GARDEN; FOR R. ACKERMANN, 101, STRAND; _LONGMAN, HURST, REES, ORME, AND BROWN; AND SHERWOOD, NEELY, AND JONES, PATERNOSTER ROW; AND J. HATCHARD, PICCADILLY_. _Price--Twelve Shillings in Boards._ 1815. EX FUMO DARE LUCEM. HOR. PREFACE. _11, Compton Street Soho._ The following pages are intended to exhibit a summary view of the new art of procuring light, by means of carburetted hydrogen gas obtained from pit-coal, and which of late has been employed with unparalelled success, as a substitute for candles and lamps, and is known by the name of GAS-LIGHT. To accomplish this object, I have given, in the first part of this Essay, a concise and popular view of the chemical theory and production of artificial light--I have explained the action of candles and lamps--I have shown the methods of measuring the comparative illuminating power of artificial light of different kinds, so as to appreciate their economical value--I have stated the proportions of combustible materials requisite for producing a light of a certain strength; with such other preliminary facts and observations as were deemed necessary to enable the reader to understand fully the nature of the new art of illumination, which it is the object of this Essay to describe. These positions are followed by a chemical view of the general nature and composition of coal--the chemical changes which this substance suffers, when employed in the production of gas-light--the different products it furnishes--the modes of obtaining them--their properties and applications in the various arts of life.