Town gas, or illuminating gas which is the literal translation of the German word “Leuchtgas” is produced in ovens wherein coal is heated strongly in the absence of air (coking). 

Dr. Nicolaus Heinrich Schilling's "Handbuch für Steinkohlengas-Beleuchtung", 3rd Volume from 1879, starts in chapter 1 with the history of gas illumination, "Zur Geschichte der Gasbeleuchtung", written by Prof. Dr. Friedrich Knapp. Prof. Dr. Friederich Knapp was a German university professor for chemistry and also wrote a book on chemical technology. The following is a summary of his essay. 

In 1659 Ph. Shirley informed the Royal Society in London about an eruption of combustible gas from a well close to Wigan in Lancashire. It was only in 1739, after he had visited this well, Dr. Clayton, Dean from Kildare was the first to describe an experiment where he produced combustible gas by distillation of coal. It took another 50 years that Lord Dundonald in 1786, after having read about this phenomena, turned his attention to the volatile products escaping from the coke ovens that were in operation on his land in Culross-Abbey. He collected tar by cooling the gases, whereas his workers figured out to catch the gases with a tube and to ignite the gases in order to illuminate their work space. 

A few years later, William Murdoch repeated the experiments  of Clayton and collected the gas in pig's bladders to use it in a lamp. In 1792 finally, he was able to steadily illuminate his sitting room in Redruth, Cornwall. Murdoch and James Watt, having heard from each others invention, met and Murdoch moved to Soho. The first apparatus to generate gas in Soho was running in the Soho-foundry in 1798, but it took some years to perfect the apparatus. In 1803 the Soho-foundry replaced all their oil lamps with gas lamps. The illumination of Philipp & Lee in Salford, a spinning plant, and the one of Henry Lodge in Halifax followed in 1805. However, every building that wanted to use gas for its illumination needed its own little gas work.    

It was first introduced for public use in England in 1812, 1817 in Paris* and 1825 in Hannover (Germany). It was introduced mainly for illuminating purposes, although it was rather unsuitable for this purpose before the invention of the gas mantle in 1885 by Carl Auer von Welsbach radically improved the brightness. However, the easy distribution, similar to the network of water pipes, made it rapidly popular.

* A small installation by Windsor in the Luxembourg gardens to light the senat, which was not working without technical difficulties (see Jean-Baptiste Fressoz, “Gaz, gazomètres, expertises et controverses. Londres, Paris, 1815-1860”).

Dr. N. H. Schilling, director of the gas work in Munich collated in 1886 data from about 600 gas works in Germany, Austria, Hungary and Switzerland. In his preface he apologized for not having followed the request of readers to depict this information in a table. One big obstacle of course is that in these countries different currency system existed, and most of them were not decimal. For example in the South of Germany a Gulden was divided in 60 Kreuzer whereas one Gulden in Austria was divided into 100 Kreuzer. 1 Taler was divided into 30 Silbergroschen (silver coins), and in the North of Germany 1 Mark was divided into 16 Schilling. At the time the value of most coins was equivalent to their value of gold or silver, so that exchange rates were fixed to the content of gold or silver. With the birth of the German Empire a new currency was introduced, the Mark, having 100 Pfennige. I therefore converted all currencies into Mark.

Less a problem was to convert the different cubic measures from Rhineland cubic foot, Prussian cubic foot, Saxonian cubic foot, Bavarian cubic foot, Hamburg cubic foot into cubic meter. Today with a spreadsheet and some formulas this has become less a nuisance.

A problem that is impossible to solve is the quality of the town gaz. As the main purpose of most gaz works was to supply the public places with light in the night, the town administrations had obliged the gaz providers to contractual minimum requirements with regard to the brightness of the light. These requirements were expressed in comparison of candle lights with candles of various thicknesses, origins, etc. Apart form that it seems an impossible task to find adequate conversion factors, the brightness is not directly related to the heating value, which is important when gas is used as a fuel for gas engines. The prices per cubic meter therefore do not take into account that a gas engine in Berlin may have a lower or higher consumption for one horse power and hour than for the same gas engine fueled with town gas from Munich or any other location.

Townyear of commencing deliveryNumber of inhabitantsprice in Mark per cubic meter
Aachen 1837 65,000 0.16
Augsburg 1848 43,000 0.30
Bamberg 1855  0.34
Basel (Switzerland) 1860 0.27
Bayreuth 1852 14,800 0.33
Berlin 1826 702,471 0.18
Bern (Switzerland) 1841 30,000 0.30
Brescia (Italy) 1859 40,000 0.33
Breslau 1847 165,000 0.26
Chemnitz 1854 0.31
Köln 1840 120,000 0.15
Danzig 1853 80,000 0.19
Darmstadt 1855 32,000 0.34
Deutz 1844 8,000 0.29
Dresden 1828 160,000 0.22
Erlangen 1858 11,202 0.34
Essen 1856 40,600 0.19
Frankfurt a.M.1828 76,900 0.23
Fürth (Bayern)1858 23,000 0.35
Hamburg 1846 280,000 0.21
Hannover 1825 79,500 0.18
Königsberg 1852 100,000 0.21
Königslutter 1867 2,342 0.21
Leipzig 1841 91,780 0.40
Lugano (Switzerland) 1864 5,500 0.23
Luzern 1858 13,000 0.34
Luxemburg 1866 14,000 0.23
München 1850 145,132 0.30
Nürnberg 1847 72,000 0.26
Pressburg (Hungary) 1856 40,000 0.34
Riga (Russia) 1858 102,000 0.34
St. Gallen (Switzerland) 1857 15,000 0.28
Stuttgart 1845 70,000 0.37
Temesvar (Hungary) 1857 25,000 0.30
Warschau (Russian Poland) 1856 211,593 0.28
Weilheim (Bayern) 1864 3000 0.45
Weimar (Sachsen)185514,5000.19
Wien (Austria)data missingdata missing
Zürich (Switzerland) 1856 20,000 0.33