liquids to flow in thin films or layers over the inner surfaces of rapidly-revolving cylindrical or conical drums, while at the same time air, gases, or vapours, subject also to centrifugal action are caused to flow over or in intimate contact with such thin layers of liquid at a considerable relative speed thereto. By this means is caused either a rapid interchange of temperature producing the heating or evaporation of the liquid or the cooling or condensation of the vapours or a combination of the two, or else an intimate mixture or a perfect separation of the liquid and the gas, as the case may be, according to the requirements and to the consequent arrangement and manipulation of the apparatus. The apparatus principally consists of a number of concentric drums of various shapes threaded on to a rapidly revolving spindle, provided with sundry devices for the proper guidance and direction of the gaseous and liquid fluids under treatment.-B.

THE inventors take a thermometer tube with an elongated bulb and place it in a metal case, which is inserted in the wall of a furnace in the ordinary way, the bulb extending beyond the end of the case, and being situated at greater or less distance from the source of heat. The bulb is enclosed in a suitable sheath of fireclay, carbon, platinum, or other material capable of withstanding intense heat, secured to the inner end of the metal case, the outer part of which carries the scale. The bulb must not be in contact with the sheath at any point.-B.

Improvements in and relating to Combined Ammonia Distilling and Refrigerating Apparatus. J. E. Fuller, New York, United States of America. Eng. Pat. 543, January 10, 1893.

The

THE invention relates to an apparatus for the production of anhydrous ammonia from the aqua ammonia of commerce; the anhydrous ammonia so obtained is intended for use as a refrigerating agent, and after being so used the ammonia is recovered and prepared for use over again by a continuous process. Fig. 1 (for illustration, see next page) shows a general view of the entire apparatus in which A is the still or separator, A6 the stand-pipes or condensers, provided with internal cold-water pipes, C is the equaliser, B the absorber, A3 the strong aqua ammoniæ supply tank, F3 the weak ammonia tank, RRR the anhydrous ammonia reservoirs, K one of the heat absorbing coils; numerous pipes connect the various parts, and valves worked by hand open or close communication as desired. The apparatus works in the following mauner :-- Steam from a boiler X passes through a coil inside the separator A, and aqua ammonia is pumped from the tank A3, through the equaliser C to a rose placed over the coil. ammoniacal liquor, trickling over this coil, is vaporised and ascends into the water-jacketed chamber A, the vertical pipes A, and the coil F. The combined cooling effect of these three condenses the watery vapour, which is discharged by a drip-trap, leaving the ammonia to pass on through the condensing coil F into the receiver R, where the vapour condenses to a liquid, and may be stored in any suitable manner, or else used for refrigerating purposes by passing it through the heat absorbing coils K. The fully expanded gas is afterwards conveyed by the manifold H to the absorber B shown in section at Fig. 2. The absorber is a cylinder B, provided with a spiral coil B', through which water circulates from the reservoir D. Weak ammonia is fed from the reservoir F3, into the atomiser B2, by the pipe b, and is still more finely divided by the perforated distributing cones B3 and deflecting plate B, thereby causing the weak ammonia water to take up the ammonia gas. The aqua ammonia, cooled by its descent over the coil B', falls to the bottom of the absorber, and collects in the cylinder B', perforated at its base, and from ther.ce a pipe B conveys the strong surface liquid back to the reservoir, to be used over again. With this apparatus it is

found that some ammonia is always left in the water at the bottom of the still A. In order to remove this ammonia, the liquid ammonia is expelled into the reservoir F3, by

B

B6

2

Fig. 2.

opening suitable valves, the pressure in the still being sufficient to force the liquid into F3. All the principal parts of the apparatus are provided with pressure gauges and level indicators.-E. G. C.

Improvements in and Relating to a System of Underground Distribution and Recovery of Anhydrous Ammonia when Employed as a Refrigerating Agent. D. Branson, Philadelphia; R. D. Thornburgh, St. Louis; and J. E. Starr, St. Louis; all of the United States of America. Eng. Pat. 544, January 10, 1893.

Το

ANHYDROUS ammonia is generated at a central station, in any suitable manner, and distributed by means of underground pipes, laid in a conduit, and following the levels of the streets. The ammonia, after use in refrigerators, boxes, or rooms along the line of route, is returned by another larger pipe to the absorber at the central station, there to be recovered and concentrated for use over again. Traps are placed at suitable points for the collection of any aqueous fluid, and to keep the pipes clear; scale traps are also provided to collect the scale, disengaged from the iron pipes by the action of the strong ammonia. provide for making repairs or changes in the refrigerators, without any loss or escape of gas, a vacuum pipe is laid alongside the flow and return pipes, so that by shutting suitable cocks, any part of the circuit can be cut off, and exhausted by the vacuum pipe. By keeping the vacuum pump constantly running, refrigerator boxes may bc repaired without disturbing the other parts of the system. A pressure-reducer is placed upon the main outflow pipe, in electrical connexion with an alarm bell, so that if the pressure rises much above the normal, the ringing of the bell at once announces the change at the central station. The valves for supplying ammonia to the cooling coils may be operated either by hand or by thermostats.-E. G. C.

and turning the vessel bottom upwards. The film is afterwards finished by thoroughly drying upon a heater. The film so made has fibres interlocking in all directions, with a surface which, although pervious to water, is of sufficient density to hold back impurities in water that has passed the preliminary screening point. The films being of asbestos do not dissolve or decompose, and are applicable to any form of portable or other filters.-E. G. C.

Improvements in and Connected with the Direct Indication of the Weight or Volume, or both, of Gases, and Apparatus therefor. A. Langsdon, London. From the firm of Fried. Krupp, Essen, Germany. Eng. Pat. 95j8, May 12, 1893.

THE object of the invention is to find the volume or weight of a gas, at any pressure or temperature, without any calculation. A volume of absolutely dry air or other gas is enclosed in an air-tight spring case, or in a "Bourdon's ring," and the alteration in volume of this enclosed gas, produced under different temperatures and pressures, is transferred by a dial train to an index finger, travelling over two concentric scales. Scale I. is constructed to read volumes, while scale II. indicates the weights, the latter scale being of course a different one for each gas.-E. G. C.

Improvements in Evaporating Apparatus. S. M. Lillie, Philadelphia, United States of America. Eng. Pat. 11,104, June 6, 1893.

THE invention has for its object the separation of suspended liquid particles from the vapours evolved during the evaporation of liquids. By means of perforated plates, the liquid is distributed over a series of horizontal pipes arranged in a closed chamber. Steam is caused to circulate through the pipes, by means of a main, causing the liquid to evaporate. The vapour so formed passes through and around baffle plates, into a prolongation of the evaporating chamber, called the subsiding chamber. The baffle plates cause the suspended particles to separate and fall to the bottom of the subsiding chamber, from whence they are drawn off by means of a pipe below. The vapour passes off in a dry state by means of an outlet pipe, placed at the upper part of the subsiding chamber.--E. G. C.

Improvements in the Process of Refrigeration and Refrigerating Apparatus. M. Wanner, Denver, Colorado. Eng. Pat. 12,121, June 20, 1893.

THE invention relates to improvements in refrigerating apparatus in which carbon disulphide is the refrigerating agent; the process is especially intended for use in abbattoirs, breweries, cold storage warehouses, and for the manufacture of ice. The figure shows an elevation of the

H

chamber of the vacuum pump. The reservoirs, pans and tubes are partly filled with carbon bisulphide, which is evaporated by the action of the vacuum pump and the vapour is drawn through the pump and forced by the return system of tubes K back into the reservoir M, being partly liquefied in its passage back through the tubes and partly by means of water entering the reservoir by the pipe N. The surplus water is drawn off by the outlet pipe O, leaving the carbon bisulphide in the bottom of the reservoir for use over again. The refrigerators are arranged in independent sets, so that in case of failure the affected apparatus can be shut off, without interfering with the remainder. For use in making ice the evaporators are immersed in the brine tank, in which is the vessel containing the water to be frozen.-E. G. C.

II.-FUEL, GAS, AND LIGHT.

Explosions of Petroleum Lamps. J. für Gasbeleuchtung, 1893 [20], 397.

THE German Imperial Commission from a copious collection of evidence, elicits evidence in support of the conclusion that scarcely 1 per cent. of the total lamp explosions have been occasioned by attempting to extinguish the lamps by blowing down the chimney. The majority of the explosions were occasioned by special circumstances, such as knocking over, or letting fall the lamps, rapid movements, or holding aslant whereby frequently ignition of the vapours in the interior of the oil reservoir or chamber, is occasioned. For prevention of explosions the following rules are to be observed::

1. The lamp must have a heavy foot with a base as broad as possible, so that it cannot tip over.

2. The oil reservoir ought preferably to be of metal, rather than of glass or porcelain.

3. The well-fitting chimney must be adjusted so that no side draughts of air can reach the flame.

4. The burner-ring must be firmly fixed.

5. The wick ought to be soft and nct too thick, also of

a width such that it can be easily drawn into the holder. 6. The reservoir ought to be filled up completely, before using the lamp; during the filling up no flame ought to be in the immediate neighbourhood.

7. The lamp must always be kept clean.

8. The extinguishing of the lamp ought to be effected, after lowering the flame to the level of the burner, by blowing down the cylinder not directly but from one side, a kind of side-blast. The direct blowing into the cylinder is to be avoided.

9. The burning lamp ought not to be exposed to a draught. If this cannot be avoided though, since the lamp must be carried about, then it must be protected from the draught by interposing a piece of paper or cardboard, &c.

PATENTS.

Improvements in the Purification of Coal Gas. J. J. Hood and A. G. Salamon, both of London. Eng. Pat. 15,925, September 5, 1892.

THIS invention deals with the elimination of "carbonic acid," "sulphuretted hydrogen," and "a class of sulphur compounds, of which the chief is carbon bisulphide" from coal gas. It is claimed that by the use of hot lime the carbon dioxide and the hydrogen sulphide are absorbed more readily than if cold lime be used, that the carbon dioxide more readily replaces the hydrogen sulphide, and

that calcium sulphide prepared from hot lime is more active in absorbing sulphur compounds than if prepared from cold lime.

Within the purifying vessels is deposited "hot hydrated slaked lime," or unhydrated lime, or partially hydrated lime, in lumps or ground. In the two latter cases the hydration is completed in the vessel itself, by the introduction of steam, or water, or both, and the heat maintained by admitting steam, or heating a portion of the gas. By these means a larger amount of carbon dioxide is arrested and a longer continued stream of hydrogen sulphide, free from carbon dioxide, sent forward, either to form hot calcium sulphide, for the absorption of sulphur compounds, or to be absorbed in "Weldon mud" or iron oxide.

Hot slaked lime for the formation of calcium sulphide is introduced into the vessels at such a time as the former vessel, known as the carbonate vessel, is becoming foul; the hydrogen sulphide driven out by the carbon dioxide is collected in the hot lime, and a very active " sulphide vessel" formed. The temperature of these vessels is maintained in the same manner as in the purifying vessels. By the use of hot slaked lime the action between ammonia, carbon bisulphide, and lime, resulting in the formation of calcium sulphocyanide, is accelerated.

For the removal of the last traces of ammonia from coal-gas by means of lime in the purifiers, the addition of calcium chloride to the water used for slaking this lime is claimed as of great assistance in the process.-R. B. P.

Improvements in or connected with Jet Apparatus for Lime and other Lights. A. Kershaw, Leeds. Eng. Pat. 16,026, September 7, 1893.

THE object of the invention is to construct jet burners so that they may be efficiently adjusted, whilst the cost of manufacture is much reduced.

In this apparatus the burner for producing the light is carried on the two gas-supply tubes. These are supported on an L-shaped bracket hinged at its upper end to a bracket projecting from a vertical tube. This tube can be rotated round a vertical rod passing through it by means of a thumb-screw; this motion moves the burner to the right or left horizontally. To raise or lower this burner there is another thumb-screw, which, by pressing on the heel of the L bracket, tilts the gas-supply tubes up or down, and with them the burner.-R. B. P.

Fig. 2

SC

Improvements in making Gas, and a Compound therefor. H. Collet, London, and M. Merichenski, Tottenham. Eng. Pat. 17,067, September 24, 1892.

IN this invention the use of a mixture of cocoanut-oil and gasoline is claimed for making illuminating or explosive gas, by passing air, a mixture of air and gas, or water-gas, through it. Either commercial cocoanut-oil or fat may be used. It is dissolved in gasoline not exceeding 0.7 in specific gravity in the proportion of one and a half pounds of cocoanut-oil to one gallon of gasoline.

This compound is specially intended for use in the carburettor described in Eng. Pat. 6909, 1892, but may be used also for enriching coal-, water-, or any other gas. -R. B. P.

Improved Apparatus for the Manufacture of Illuminating Gas. H. E. Newton, London. From R. N Oakman, jun., Greenfield, Mass., U.S.A. Eng. Pat. 17,394, 'September 29, 1892.

THIS invention relates to the manufacture and carburetting of water-gas. With this plant pressure is not required, the steam and air being alternately drawn down through the incandescent fuel by an exhauster. In this manner the

KC

gases from the ovens pass out through vertical ports in the crown into the flue C, and out of C through lateral ports into the flue C1. The latter has a cross partition at its centre, which divides the gases into two parts, one going to each end of the flue, and then through the dampers S into the flues C2, and out through the ports O O into the hearth chaunel S C. The necessary air is admitted through Pf from the cooling channel K C. When by-products are to be recovered the gases are exhausted direct from the ovens, or from C and C', the dampers S being shut. After treatment the gases are admitted under S into the flues C2. -R. B. P.

Improvements relating to Apparatus for the Manufacture of Water-Gas. A. G. Glasgow, Westminster. Eng. Pat. 6324, March 24, 1893.

THIS invention relates to an oil heater for water-gas apparatus. In the gas conduit F, between the superheaters B and C and the purifying chamber Q, is placed an oil heating tube G. Along the centre line of this is a rol H (or a tube closed at both ends) welded to the top of the tube, which is there closed. The rod is kept concentric with the tube by means of lugs on it. The object of this rod is to cause the oil, which enters the lower end of the tube, to ascend in

Feed Device for Gas Producers. C. W. Bildt, Worcester, Mass., U.S.A. Eng. Pat. 10,585, May 30, 1893. THIS invention relates to improvements upon the apparatus described in Eng. Pat. 20,462, 1890, and consists of an apparatus for feeding in the fuel and evenly distributing it.

Attached centrally to the producer cover is a hopper, in the form of a truncated cone, and below this is a horizontal disc, carried by a sleeve which is continuously rotated, by suitable gearing, round a central shaft.

To the lower end of the latter are attached two distributing blades, one of which converges spirally towards, and the other diverges spirally away from, the shaft carrying them, one curve finishing where the other commences, both being in the same horizontal plane. The coal falls from the hopper on the rotating horizontal disc, and from this on to the distributing blades, whence it is thrown on to the bed in spiral lines, and in a uniform and even layer. The gearing for rotating, raising, and lowering the disc and blades is described.-R. B. P.

A Gas Light Intensifier by the use of which any Ordinary Gas Burner will give a Greater Amount of Light. J. T. Guthrie, Leith. Eng. Pat. 15,213, August 24,

1893.

A MARKED increase in the amount of light given off by the same quantity of gas in any ordinary burner is claimed to be effected by use of a metal cylinder fitting over the burner, and having projecting wings or sides. A burner with these permanently attached is also described.-R. B. P.

-R. B. P.

III.-DESTRUCTIVE DISTILLATION, TAR PRODUCTS, Etc.

Asphalt Mines in Syria. Reports from the Consuls of the United States, 42 [153], June 1893, 228-230.

OF the four asphalt mines known to exist in Syria, the one situated in the vicinity of Hasbaya, about 40 miles southeast of Beirut, is the most important. It yields a product little inferior if not equal to that derived from that wellknown source, the Dead Sea, and is the only mine in Syria from which asphalt is at present obtained. The working of the three other mines, situated at Sohmor (30 miles south of Beirut), Ain-Ettineh village (70 miles east of Beirut), and in the valley of the Dead Sea, respectively, is strictly interdicted by the local Turkish authorities. Until 1860 these mines were almost completely neglected, small quantities of asphalt only being dug, free of tax, by the natives and applied by them to their vines as an insecticide. In 1864 the working of the Hasbaya mine (the Sultan's private property) was placed upon a commercial basis and is now carried on with marked success by the firm Absy & Co., who have held the mine sirce 1888, the condition of the lease being that 65 per cent. of the asphalt extracted should go to the agents of the imperial private treasury. The amount of asphalt obtained by this firm during the last five years is estimated at 5,400 tons, the price of the product in the foreign markets being at present from 8 69 dolls. to 9 65 dolls. per 100 kilos., whilst at the commencement of the working of this mine it was 19.30 dolls. The Syrian asphalt, which is invariably exported in its natural state, is subjected to an export duty