The name briquette, which is now used for every variety of artificially formed combustible, was originally used in Paris for fuel formed from peat with addition of water and plastic clay; later it was applied to fuel formed by pressure at a high temperature from good agglomerating coal, but without addition of a bond, to distinguish them from those termed "pérats," under which name were included the fuel first made by Bérard and Givors from bituminous coal with tar, pitch or other bond. Numerous other names, such as "charbons agglomérés," "houilles agglomérés," or for short, "agglomérés," in France, "briquettes de charbon" in Belgium, "patent fuel" or "compressed fuel" in England and North America, "kohlensteine" or "kohlenziegeln" in Germany, were all used in a restricted sense for pressed fuel from bituminous coal only, while under "combustibles artificials" and "artificial fuel" were embraced every sort of artificially prepared fuel. In Germany, pressed brown coal was designated by such generally used terms as nass-press-steine (also presskohlensteine) and darrsteine (or darrkohlensteine), in accordance with the two different methods of preparation.

Numberless experiments for the preparation of coal for use by pressing were conducted in different directions and by different methods, but the difficulties to be overcome were very considerable, both from a chemical and a mechanical point of view, and it required a very long time after the principle was understood before it was found possible to enter upon the manufacture successfully, and for this reason the real production of briquettes from bituminous coal may be said to date only from 1860, and of brown coal from 1870. Since that time the improvement has gone on steadily, and there is hardly any doubt that materials now regarded as unbriquettable in this manner may finally, under sufficient pressure, be "

Preissig, E. Die Presskohlen-Industrie, Freiberg, in Sachsen, 1887.