and in the employment of refrigerating saline mixtures, for the more effectual cooling of the spirit in warm climates, or in warm weather.

This invention has been patented about six years, which circumstance gives it greater claims upon our admiration, than if it were the invention of this precise period of time, so fraught with great improvements in the art of distillation; many of which, however, appear to us to have been indebted in a great degree, to this fine example.

le the body of the still, (that part where the vapour is generated) there is no improvement proposed, but an enlarged capacity of its globular hear, to cause the watery particles to fall back into the still; this part of the apparatus we have omitted in our diagram, as it requires no additional explanation; the engraving, therefore, relates wholly to the apparatus for condensation.

a is the termination of the neck of the still which conveys the vapour into the upper drum" b, whence it is divided among a number of small vertical tubes c, which the patentee says, should not exceed of an inch in their interior diameter. As the tub inclosing this apparatus is filled with cold water, the condensation immediately commences in the upper drum, and is completed in its subsequent progress through the vertical tubes, and the lower drum" d. From thence, the fluid runs down a central neck e, into the trap f, from the upper part of which trap it enters the cooling worm g. It is evident that the trap f is, in working, always partly filled with liquid, and the neck e being immersed therein, any vapour which may have escaped condensation can pass no further. The trap ƒ has a

funnel-shaped bottom, from which a pipe h passes through the coils of the worm, and through the side of the tub, where it is furnished with a cock, for the purpose of drawing off any impure spirit, which may be separated from the wash in the first stage of the process; and to discharge what may remain in the trap when the process is over. To the trap f is also attached another pipe i, called the safety pipe, for the purpose of allowing "the egress and ingress of atmospheric air, from, and to, the condenser, to prevent both pressure, and a vacuum, therein." The coils of the cooling worm are made octangular; the worm itself is made flat, and of considerable breadth: a transverse section of it is exhibited in the separate figure k, which shows it to be in the form of a parallelogram, whose longest sides are four inches, and its shortest half an inch wide. This octangular worm, after making six complete turns, assumes a circular shape and diverges off to pass through the side of the tub; at its end, outside the tub, which is made a little tapering, is fitted, and is to be occasionally applied, a crane-necked pipe, which pipe may be elevated or depressed at pleasure, for the purpose of keeping three or more of the coils of the worm full of liquid. This crane-necked pipe is intended to be applied in hot weather, or hot climates, to cool the spirits more effectually, and prevent their evaporation, by subjecting the same in a greater degree to the effect of the cold water in the worm tub.

An additional apparatus to be used in hot climates, of undoubted utility, is likewise recommended by the patentee, and claimed by him as his invention. It consists of another pipe m, into which the discharging end of the crane-necked pipe is made to enter, and which pipe, after passing the end of the trough n, is made of a very broad flat shape, and running the whole length of the trough, (which may be of any extent;) it is then to return by a very slight descent, so as to run back very gently into the funnel of the pipe which conveys it into

the receiver.

The trough n may be supplied with Glauber's salts and nitre, or any saline mixture capable of producing intense cold, for the more effectual cooling of the spirit; the trough may be placed upon wheels and axles, for the convenience of bringing it to, and conveying it from, its required situation.

The patentee further recommends, but does not claim it as a patent right, that the ash-pit of this still, as well as of stills generally, be furnished with a plate iron door, in which is to be introduced near its top, one or more registers, as shown in the separate figure at o, the apertures in which may be closed, more or less, to produce the required draught, and thereby enable the distiller to check, or increase, the ebullition at pleasure, and with the greatest facility.

1

GAS APPARATUS.

Account of the apparatus for which a patent has been obtained by Wm. Vere, engineer, and Henry S. Crane, manufacturing Chemist, for improvements in the manufacture of Gas for illumination; and especially for the decomposition of coal tar for that purpose.

In the generation of sub-carburetted hydrogen gas, from coal, great inconvenience has been sustained by the deposition of adhesive matters in the pipes leading from the retorts, by which they gradually

became choked up; it, in consequence, became frequently necessary to suspend the process, for the purpose of clearing out the deposit. A considerable quantity of tar is also obtained as a separate product in the gas manufactories; in some of them, this tar was afterwards decomposed, for the purpose of generating gas, (which it yields in considerable quantity) but it was discovered, that the tar, thus employed, caused a greater evil in the pipes by a deposition of asphaltum, which quickly rendered them unserviceable: besides this, it was found that the gas produced from this material afforded but a feeble light, and emitted much smoke: for these reasons, the decomposition of coal tar was discontinued in most manufactories.

As a remedy for these evils. Messrs. Vere and Crane have devised the invention delineated in the accompanying engraving. The specification states the apparatus to be applicable to the distillation of coal, coal-tar, tar-oil, oil, vegetable oil, animal oil, and all other solid or liquid matters, from which carburetted hydrogen may be obtained; and the process consists in introducing a constant stream of water into the retort, or a current of steam into the exit pipe; which, mixing with the volatile matters, as they rise from the substance under decomposition, causes them to fall down again into the retort, without proceeding further to choke up the pipes, while the more gaseous products pass on through the steam, in a more pure state, to be afterwards treated in the usual way. The gas obtained from tar by this process, is said to burn with a brilliant white flame, instead of the dull, smoky light, as before mentioned.

Fig. 1 is a front elevation of the improved retort, set in the brickwork of the furnace. Fig. 2 is a vertical section of the same, showing more advantageously its construction, and the mode of operating, The letters have reference to the like parts in each of the figures.

a is the ash pit, b the furnace, cee the flue winding round the retort; d the retort, with its lid fastened in the usual way, by a cross bar and screw; e the exit pipe, through which the gas escapes as it is generated; f is a wrought-iron pan, or tray, to hold tar, or other liquid matter to be distilled; g a supply pipe to f, leading from the cistern, or reservoir, h; i is a water pipe, and k a cistern of water.

When tar, for instance, is to be operated upon, the retort partly filled with coke, or broken bricks, is to be brought to a bright red neat, which may be ascertained by inspection through the holes oo, shown in fig. 1, which are provided with stoppers; the cock of the water pipe is then to be opened, to admit water to flow, in a slender stream, into the retort, the heat of which immediately converts it into vapour; this done, tar is to be admitted from the reservoir h to flow through the pipe g into the pan f, where it is quickly decomposed; the gas, as it ascends and enters the exit pipe, necessarily passes through a large volume of steam, which causes an instant precipitation of the carbonaceous matters, which would otherwise lodge in the pipes, and ultimately obstruct the passage of the gas through them. The gas, thus relieved of the principal contaminating natters, has then to pass through the ordinary purifications, by which it is ultimately brought to a state of great purity, for consumption.

When coal, or other solid matters, are to be decomposed, for ob taining the gas, the pan f, the pipe g, and the reservoir h, are to be removed, and the operation is to be conducted without them; retaining, however, the use of a current of steam, as in the former case. The quantity of water required for this purpose, will depend upon the nature of the material under distillation; but, in general, eight or ten gallons of water to 1000 cubic feet of gas will be found adequate to the precipitation of the carbonaceous matter. The stream of water should of course be constant and uniform; and it would be desirable to introduce a current of steam from an engine boiler, if there be one on the premises, in lieu of the water, especially when operating upon coal.

Description of the apparatus for obtaining, and purifying, gas from coal, for which a patent was obtained by Mr. Hobbins, Ironmonger.

THE accompanying drawings represent a new construction of retorts for the generation of the gas, and an improved apparatus for its subsequent purification. The advantages expected to result from these arrangements are, first, an increased facility in charging the retorts with coal, and afterwards in discharging them of the coke