We do not pretend to decide, which of the preparations above-mentioned is preferable; as they are all eminently calculated to introduce economy in one of the most useful articles of domestic convenience—fire.
Beside these compositions, various machines have been invented for saving fuel, of which the following are worthy of notice:—In May, 1792, Mr. David Frearson, of Liverpool, obtained a patent for machinery and operations for the purpose of saving fuel, in the process of evaporating water from solutions of salts, or the waste or leys of soap-makers; and which may be applicable on other occasions, where the evaporation of water from substances holding it in solution is required. For the particulars of this invention we refer the reader to the 9th vol. of the "Repertory of Arts and Manufactures," where he will find the whole process amply detailed.
A patent was likewise granted, in June, 1798, to Mr. George Blundell, of Bethnall-grien, Middlesex, for his invention of a machine calculated for the purpose of saving fuel, and preventing dirt or dust from fires, which he calls an "Economical Receiver."—The apparatus consists of certain receivers, or boxes, formed of metal, either simple, or compound, and which are either square, oval, or of any other shape that may be required, in order to be fitted beneath any kind of grates, stoves, or fire-places. Over this receiver is fixed a grating, or net-work of wire, which intercepts the cinders, and suffers the ashes fall into the lower part of the vessel. There are likewise sliders, and other pieces of machinery; an explanation of which is inserted in the 10th vol. of the work above cited.
FULLERS'-EARTH, or Argilla Lithomarga, is a species of clay, of an ash-coloured brown, and presents various shades, from a very pale to nearly a black colour: it is in general of a greenish cast.
This earth is hard, firm, and of a compact texture, but soft to the touch, and neither stains the hands nor easily breaks between the fingers. Its surface is somewhat rough and harsh; it dissolves easily in the mouth; and, in a slight degree, adheres to the tongue. When thrown into water, it does not cause any effervescence, but gradually increases in size, and subsides in a fine soft powder.
The largest stock of the finest fullers'-earth in the world is obtained from the pits at Wavedon, near Woburn, Bedfordshire; where strata of it are found at the depth of ten or twelve feet from the surface of the ground. This earth is also found in abundance, and of a good quality, in certain pits near Brick-hill, in the county of Stafford; near Ryegate, Surrey; Maid-stone, Kent; and in the vicinity of Nutley and Petworth, in the county of Sussex.
Incalculable quantities of fullers'-earth are consumed in this country, in the scouring of cloths, stuffs, &c.; for which it is of the greatest utility, as it imbibes all the grease and oil used in the preparing, dressing, &c. of wool. For this reason, it is declared to be a contraband commodity, and is prohibited to be exported, under the penalty of one shilling for every pound weight.—As an article of domestic economy, it might be more frequently employed than it is at present, especially in the clean-
