the branch of the main line, by which the goods are to arrive each of which is to receive two, three, four, or more trucks loaded with coals or other goods in bulk, such short lines of rails having at or near the one end the apparatus for receiving the coals to which point the trucks are brought in succession to be unloaded. At each end of these short lines of rails (when they are parallel) are disposed lines of rails transversely thereto, and at a lower level, on which transverse rails are placed traversing trucks on which the coal trucks are run in order that they may be traversed. The traversing trucks are provided with rails to receive the coal trucks. Patent completed

2194 W. CLARK. Improvements in felting hats and other felted fabrics, and in apparatus for the same. (A communication.) Dated August 25, 1866.

This invention is not described apart from the drawings. Patent completed.

2195 J. F. M. POLLOCK. Improvements in machinery or apparatus for pressing bricks, tiles, corbels, or other plaster

work. Dated August 25, 1866.

This invention consists, first, in the external arrangement and self-contained nature of the machines, the compact rectangular form of frame in which all the working parts are enclosed and protected from the action of dust or other injury, even the ends of the holes in which the shafts run being capped. Secondly, the employment of a spring or other maintaining power or accumulated force, and the connection by that means of the continuous and intermittent motions. Thirdly, the arrangement of the cylinder and valve gearing beneath the die, and the means of applying direct pressure to the brick by the use of two crossheads and side rods. Fourthly, the means employed for obtaining all the self-acting motions from one shaft. And, fifthly, the independent action of the cylinder and other parts of the machine being such that very small driving power is required, the pressure given not being derived from the power which drives the gearing. Patent completed.

These seg.

one side of the rim. The interior surface of the said rim
is turned perfectly true and forms the bearing surface for
the clutching device. The said clutching device consists of
two segments fitted to slide freely in guide ways, formed
in a plate, which is firmly fixed by means of keys or set
screws upon the shaft on one side of the pulley. The said
segments are provided with a flange at their outer extre-
mities, which flange is curved to correspond with the
curve of the interior surface of the pulley.
ments are forced into contact with the said surface, when
required, by means of levers hinged or jointed upon
suitable fulcrum pins fixed upon the segment plate. These
levers at a point near their fulcrums pass through and fit
into slots or apertures formed in the segments, the said
slots having curved edges to enable the levers to work pro-
perly therein. The ends of these levers extend through
the segments and lie in the proper position to be operated
by a conical collar fitted to slide upon the shaft, the said
justment, by which the pressure of segments upon the rim
ends being provided with set screws or other means of ad-
of the pulley is regulated. Patent abandoned.

2198 G. HASELTINE. Improvements in churns. (A communication.) Dated August 25, 1866. This invention consists chiefly in the mode of forcing air into the contents of the churn, and in the peculiar arrangement of a series of breakers, against which the milk is thrown during the process of churning. The churn is composed chiefly of a cylindrical vessel of wood or other suitable material, in the centre of which an upright revolv ing shaft or spindle is placed, carrying a set of beaters, by whose actions the required agitation is imparted to the milk and other contents of the churo. At the lower end of the upright shaft, a little above the bottom of the cylindrical vessel one or more horizontal tubes are fixed, extending from the centre of the said shaft outward. The tubes are formed of tin or other suitable material, and are open at their outer end, having orifices of a smaller area at a point near the spindle. Other tubes are connected to these 2196 E. BROOKS. Improvements in breechloading fire-horizontal tubes, and extend upward therefrom by the side arms, and in cartridges for breechloading firearms. Dated of the upright shaft, by which they are supported in small August 25, 1866. sockets or other convenient means of attachment which These improvements in breech-loading firearms relate allow the tubes to be readily removed when required for principally to breech-loading firearms in which the breech cleaning or other purposes. These vertical tubes are made of the barrels is opened by the turning aside of the barrels to extend upward above the level of the contents of the on an axis parallel with the axes of the barrels, but is also churn, and are open at their upper ends to admit the air. in part applicable to breech-loading firearms of the kind When milk is placed in the cylindrical vessel it will rise to called drop-down or snap guns. The inventor's improve the same level in the vertical tubes, but when the central ments in breech-loading firearms are as follows:-He shaft carrying the said tubes is set in motion, the centrimakes the front end of the axis, upon which the barrels fugal force derived therefrom will throw the milk out turn aside, of smaller diameter than the hinder and through the horizontal tubes. This produces a partial screwed part of the said axis. He also causes the said axis vacuum in the tubes, and causes the air to rush down to project through the lump on the underside of the barrels through the opening in the upper end thereof. The air the said projecting part being made angular. A spring on thus drawn into the tubes is immediately thrown out therethe under side of the rib between the barrels bears against from by the centrifugal force produced by the continued the said angular part and holds the barrels with a slight rotation of the upright shaft or spindle, and by the friction degree of force when they are turned either into their closed of the milk passing through the horizontal tubes from the or open position. To the underside of the body of the gun, inner to the outer orifices therein. The aerification of the and below the axis on which the barrels turn, is a project- contents of the cylindrical vessel, if further assisted, by ing piece or bracket, against which a corresponding piece causing the extremities of the horizontal tubes to revolve on the lump connected with the barrels works and bears. under the lower extremities of the breakers. This partially By these two parts a bearing or support beneath the axis prevents the contents of the cylinder following closely the is provided, whereby the breech ends of the barrels are kept horizontal tubes while they rotate under the said breakers Armly to their bearing against the face of the break-off. and causes the formation of empty spaces within the conThe lump on the under side of the barrels screws on to the tents of the cylindrical vessel, the said spaces being imaxis in the usual manner. Or portions of the screw threads mediately filled by the air drawn through the horizontal both in the lump and on the axis may be cut away, so that tubes into the milk or other contents of the churn, which by presenting the lamp to the axis in a particular position, are thereby effectually aerified. The beaters are attached it may be passed by a sliding motion on to the said axis, horizontally to the central upright shaft, and are formed after which, by a rotary motion, the screw threads of the preferably of flat strips of wood secured to the said shaft in axis and lump respectively may be made to engage with a slightly inclined position. Patent abandoned. one another. A groove is made across the upper part of the fore end of the axis, in which a pin passed through the lump engages and prevents the unscrewing of the barrels from the axis, excepting on the withdrawal of the said pin. When the barrels are in proper position for discharge they are fixed by means of a spring lever on the upper side of the trigger guard, the end of which passing through a slot in the projecting piece or bracket described on the body of the gun, takes into a depression in the bracket on the lump. By pressing the spring lever upwards the barrels are liberated and may be turned aside for charging. Or the barrels may be fixed by a slide on the tang of the break off, which side carries a vertical bar, having two horizontal pins, the upper one taking into a hole in the upper rib, and the other into a shallow depression in the lower rib. The slide is urged forward by a spring, and as the barrels are brought into position for firing the slide and pins are pushed back by the breech end of the barrels acting on the lower pin, and when the barrels are brought into position for firing the two pins spring into the holes described and fix the barrels. The barrels may be liberated by pressing a thumb plate on the slide. The brackets on the under side of the body and barrels may be applied to drop down guns. In this case the bracket on the barrels is made narrow and works through a slot in the body of the gun. The surfaces of the two brackets are made of a curve struck from the centre, on which the barrels turn. Both the methods of fastening the barrels during discharge herein before described may be applied to drop down guns. The inventor's improvements in cartridges for breech-loading firearms are as follows:-He enclose the shot in a small bag or envelope made of paper, linen, or other fabric, which, by treatment with nitric acid, has been made combustible and similar in its nature to gun cotton. After placing the powder in the cartridge case the inventor inserts a wad perforated in its middle, and ther introduces the bag or envelope containing the shot, the cartridge being finished in the ordinary manner. On discharge the fire of the gunpowder is communicated through the hole in the wad to the combustion bag or envelope containing the ahot, which burns away rapidly but not until the shot has been projected to a considerable distance. By this means the spreading of the shot is diminished and more accurate firing obtained. Patent abandoned.

2197 C. M'FARLAND. An improved friction clutch for starting and stopping machinery. (A communication.) Dated August 25, 1866.

This invention consists in the peculiar arrangement of parts whereby the surfaces of a pulley and clutching device are brought more directly and forcibly into frictional contact with each other and whereby the construction of the said parts is greatly simplified and rendered more substantial than heretofore. The pulley is fitted to run loosely upon its shaft, and is provided with a boss of suficient length to support it steadily on the said sbaft, the arms or plate connecting the rim and boss being formed on

2199 C. T. PORTER. Improvements in steam engines.
(Partly a communication.) Dated August 25, 1866.
This invention relates, firstly, to the construction of an
equilibrium slide valve, and to the means for preventing
the pressure of steam upon the said valve, and for keeping
it steam-tight upon its bearing surfaces, and secondly, to
the means for diminishing the loss of heat by conduction
from the cylinders of steam-engines. The said slide valves
are more especially designed for use in steam-engines in
which there are separate valves for the admission and ex-
haustion of the steam at each end of the cylinder, each
valve having an independent motion. The object desired
to be attained by the novel construction of the slide valve
is the direct admission of steam into one part through
passages on its opposite sides, which are opened and
closed by the sliding of the said valve. Patent completed.
2200 E. LAMB. Improvements in the construction of
apparatus for cleaning and polishing boots and shoes, such
apparatus being also applicable to other purposes. Dated
August 27, 1866.

This invention consists in certain combinations and ar-
rangements and mechanism which are well adapted for
the operations of cleaning and polishing boots and shoes,
and for other like or analogous purposes.
One of the mo-
difications of which this invention is capable, is as fol-
lows:-One or more wheel or wheels is, or are, mounted
upon suitable bearings attached to a stand, the revolu-
tion of such wheel or wheels being effected by means of a
winch and connecting straps, or by a treddle and crank, or
by any of the well-known methods suitable for such pur-
pose. To the sides of the periphery or peripheries of the
wheel or wheels are attached brushes, the same being se-
cured to the wheel or wheels, by means of screws or other
suitable contrivances, so as to be readily removable for the
purpose of substituting brushes of any desired degree of
hardness adapted for the different purposes of boot and shoe
cleaning and polishing, or the wheel or wheels, may be re-
movable so as to be replaced by others of a different charac-
ter; upon the wheel or wheels being caused to revolve and
the boot or shoe pressed against the brushes, the latter re-
moves the dirt from the former in the case of hard brushes
being employed, whilst by the use of brushes of a different
and suitable character, the operation of polishing may be
performed. Patent abandoned.

2201 W. PIERCE. Certain improvements in the method
of purifying gas, whereby its illuminating properties are
improved, and in the apparatus connected therewith. Dated
August 27, 1866.

and arrangement of the apparatus for the purpose. Patent abandoned.

2202 J. NORTHROP. Apparatus to be used in the fringing and trimming of shawls, mantles, and other fabrics requir ing fringes or trimmings. Dated August 27, 1866.

This invention has reference to the fixing or securing fringes or trimmings already prepared upon shawls, mantles, and other fabrics requiring the like. This operation it is customary to effect by means of ordinary sewing machines, but from the nature of the work it is irregular when completed. To obviate this defect is the object of this invention, and the inventor effects it by the use of a guide plate fixed on the front part of the table of the machine. The the length of the machine, and may be made of thin plate, one part of the guide, when fixed, lies in the direction of or wire of any convenient metal, turned over twice, somewhat in the form of a square within a square. The edge of the article to he fringed or trimmed is passed into this remaining part of the guide consists of a piece of plate or guide, and thus forms a hem or turn over preparatory. The wire, with a simple turn over, placed at right angles to and behind the previous one, and the depth of such distance from the before named guide being regulated as the depth of the fringe or trimming (which is passed through it) from the edge of the shawl or other article to be trimmed may necessitate. By this arrangement, therefore, the rela tive distances of the point where the fringe or trimming is sewn to the article under operation having been determined, the machine being put in motion, uniformity is attained, and also a much larger quantity of work effected, as on the machine being put in motion it carries the material for ward in the usual manner, and also does not require that Patent constant attention which is at present the case. abandoned.

This invention relates to the purifying of coal gas, and to the improvement of its illuminating powers, by bringing it into contact with a certain light oil made from tar, or with certain other mineral oils in a heated state, whereby the gas imbibes or becomes impregnated with an amount of carbon given off or emanating from the heated oil. These improvements consist in the application of steam or hot water to the heating of the said oil, and in the construction

2203 C. E. BROOMAN. Improvements in or connected with carriage brakes. (A communication.) Dated August 27, 1866.

This invention relates to automatic brake apparatus for omnibuses and other four-wheeled vehicles, with the view of preventing accidents and diminishing the labour of the horses in sudden stoppages, or in descending hills. It consists in an arrangement of slide and movable bolt or pin, by which the brakes are applied to the back under frame of the carriage by the stopping of the horses, and without any other intervention. When it is required to annul or prevent the action of the slide a simple mechanism operated by hand is employed. Patent abandoned.

2204 H. A. DUPRENE. Improvements in the manufacture of beer and other alcoholic liquids, and in the apparatus employed therefor. (A communication.) Dated August 27, 1866.

The patentee claims, firstly, the rapid cooling of the brewings to lower temperatures than that of well water, if required, by the successive evaporation and by the con densation produced by the mechanical pressure of ammonia, methylic ether, or other analogous volatile liquid, as Secondly, the described and represented in the drawings. regulating the temperature of the fermentations either by means of currents of cold water cooled down to temperatures below that of well water, if required, by the successive evaporation and by the condensation produced by the mechanical pressure of ammonia, methylic ether, or other analogous volatile liquid, as shown in the drawings, or by the evaporation and self-condensation of the said volatile liquids, as described. Thirdly, the maintaining the temperature of vaults and cellars under the temperature of well water, if required, by the circulation of air and water cooled by the successive evaporation and by the condensation obtained by the mechanical pressure of the said volatile liquids or their analogues, as described and represented in the accompanying drawings. Fourthly, the construc tion and application of apparatus for cooling the brewings in the manufacture of beer and other alcoholic liquids, and the places or cellars in which the same are stored, as described. Patent completed.

2205 W. KRUTZSCH. Improvements in the construction and combination of breechloading and repeating firearms and ordnance, and in the cartridges for use in the same. Dated August 27, 1866.

This invention is not described apart from the drawings. Patent completed.

2206 T. DAVIS. An improved method of or apparatus for ventilating dwelling houses or other buildings. Dated August 27, 1866.

The patentee claims the use in various forms and manners, as set forth, of what is here styled a "perflator," in combination with the "perhaustor," and the occasional use (where necessary) in conjunction with these of a gasburner, or other rarefying agent, to give additional force to the current of air, so as to draw off from the room or apartment the foul, heated, or contaminated air contained therein. Patent completed.

2207 J. FARMER. Improvements in apparatus for regulating the flow of steam into steam engines by what are commonly called expansion cut off valves. Dated August 27, 1866.

This invention has reference to a former patent granted to L. B. Pitcher, dated October 2, 1851 (No. 13759), and according to the aforesaid invention the regulating rod of the hydraulic apparatus acted through the medium of rods and levers upon the ordinary throttle valve. By the present invention the inventor causes the said regulating rod to act upon an expansion cut-off valve. Pate it abandoned.

2208 J. PROCTOR. Improvements in chimney pots or terminals. Dated August 28, 1866.

This invention has for its object the construction of a chimneypot or terminal that shall effectually prevent a down draught. For this purpose the inventor forms or fixes inside such pot or terminal two or more sloping plates or projections, situated at any convenient distance one above the other. These plates or projections spring alternately from opposite sides of the pot, and project upwards at any suitable angle, each one passing somewhat beyond the centre line of the pot, so that the edge of the one above overhangs the one below. At the part of the pot from which these plates or projections spring, apertures are formed in the sides of the chimneypot, so that any wind entering the top of the chimney will be caught by and made to pass down the upper surfaces of the projections or plates, and will thus be conducted out through the beforementioned apertures; and, in the same way, air entering through the side apertures will pass along the sloping sur faces and be conducted up, through the top of the pot, into the open air again. By making the edge of the upper

This invention is not described apart from the drawings.ments in the manufacture of stays, corsets, and riding 408 S. Osborne, Castle-square, Falcon-square. ImprovePatent abandoned.

purposes of ventilation.

446 A. A. Fousset, Rue des Acacias, Paris. Improvements in the manufacture and treatment of varnished or patent leather, oil or varnished cloth, and other like materials.

448 A. Beniest, Ghent, Belgium. Improvements in governors for regulating the movements of steam engines that they never can deviate from the speed required.

450 E. Brasier, New Cross, engineer. Improvements in machinery for scutching flax or other fibrous materials, and also for opening and straightening fibrous materials (which have been previously made up into yarns and threads), in order to prepare the same for spinning and other purposes.

452 H. Y. D. Scott, Ealing, Lieut.-Col. Royal Engineers. Improvements in constructing the floors and roofs of houses and other buildings.

456 T. Archer, jun., Dunstan Engine Works, engineer, Gateshead-on-Tyne. Improvements in machinery or appa1m-ratus for breaking and grinding stone ores and other hard materials.

460 A. Albini, New Broad-street-buildings, Capt. Italian Navy, and F. A. Braendlin, Birmingham, mechanical engineer. Improvements in breechloading firearms.

462 R. Kunstmann, City-road, engineer. An improved marble, metal, and other smooth surfaces, machine for cleaning and polishing the surface of glass,

468 J. Bishop, North Audley-street. Improvements in breechloading firearms and ordnance. 470 G. Haseltine, Southampton-buildings, Chancery. lane, civil engineer. Improvements in wheels for carriages and other vehicles. (A communication.) 472 E. G. Brewer, Chancery-lane. Improvements in machinery for obtaining and applying motive power. (A communication.)

head, Renfrewshire. Improvements in motive power en-, 474 J. Weems, Johnstone, and T. Robertson, Kennisgines.

Improvements in apparatus for teaching alphabets and 476 B. Mitford, Northumberland Lodge, Cheltenham. reading.

478 J. Robinson and J. Smith, Rochdale, engineers. Improvements in applying motive power to saw frames. 480 J. F. Bland, Sandgate, Kent, Capt. H.M. 76th

392 J. H. Johnson, Lincoln's Inn-fields. Improvements
in breechloading firearms. (A communication.)
396 A. V. Newton, Chancery-lane, mechanical drafts-Regiment. Improvements in breechloading firearms, partly
man. Improvements in sewing machines. (A communi- applicable to other arms.
cation.)

Dated February 22, 1867. shire. Improvements in rag engines. 482 J. R. Crompton, Elton Paper Mills, Bury, Lanca

484 J. Harrison, Liverpool, shipowner. Improvements in other floating structures. apparatus for removing seaweed, shellfish, and other foreign matters from the bottoms or submerged parts of ships and

485 W. West, Tredenham House, St. Blazey, Cornwall, bers, Moorgate-street, City, mining engineer. Improvecivil engineer, and J, Darlington, Moorgate-street Chamments in apparatus for counterbalancing pump rods,

588 G. M. Garrard, Gracechurch-street, City, civil enginery. neer. Improvements in apparatus employed in mowing and reaping.

590 E. Thring, Uppingham, Rutland, clerk. Improvements in stoves or fireplaces.

and useful fabric for elastic stockings, stays or corsets,

592 A. C. Laurys, Louvain, Belgium, merchant. A new

bandages, and other similar and analogous articles.

NOTICES OF INTENTION TO PROCEED WITH
PATENTS.

From the London Gazette, March 19, 1867.

2880 C. F. Spagnoletti. Communicating in a railway train.

THE

MECHANICS' MAGAZINE.
MAGAZINE,

THE

LONDON: FRIDAY, MARCH 29, 1867.

THE PROBLEM OF THE TORPEDO. THE problem of the torpedo is one which is attracting the attention of all thinking men, and one moreover to which an amount of interest attaches which must go on in creasing until the problem be solved. Whatever may be said against the torpedo as an arm of war by naval men-and we know such contrivances are ever distasteful to the true British sailor-there is no disguising the fact that sooner or later it must be adopted for general service. Our taste in the matter of its adoption will by no means be consulted by those who may have to use it against us, should such a contingency arise, so that there is no alternative but to go with the stream and be prepared to meet our foes, should we have any, on an equal or if possible a superior footing. It is quite time, too, that those to whom our defences are entrusted should understand that the invention of engines of war is progressive, and that its progress cannot be stopped, nor its results suppressed. Further, as the torpedo promises to become the naval arm, it behoves our naval men, who will have to deal with it in future wars, to acquire without further loss of time a knowledge of its construction, its every detail, and its management at sea. This latter is a very important consideration, and one to which but little attention has as yet been given. Too much stress has been laid upon the torpedo as an arm for coast and harbour defence, whilst its applicability to ocean warfare has been to a great extent lost sight of or ignored. It is at sea that a properly designed torpedo can be most easily and effectively applied by vessels adapted to its service. It is at sea, therefore, that we should encounter monster war vessels. We should not permit them to approach sufficiently near to be within the range of land batteries, nor within the scope of action of torpedo boats. An enemy should never be allowed to come near enough to our shores to require harbour defences, but if they did escape the torpedo vessels outside, there should be others, with steam up, ready to attack them at the entrances of harbours. But with an efficient torpedo and proper management, even this contingency need hardly be feared, although it should be provided against.

which mode of attack should be adopted. By a recoil of 4 2-16in. Horsley's powder in a very simple arrangement of levers outside similar state of meal, and with a similar presthe torpedo, and an equally simple discharg-sure of 400lb. per square inch, showed a recoil ing apparatus inside, the torpedo is exploded of no less than 11, 9-16in. These results afford when in hugging contact with the enemy's some idea of the relative power of Horsley's ship. Care has been taken that the shape of powder and the best gunpowder. We lately the shell shall embrace the following essen- examined some blocks of elm which had been tials-1. Large amount of surface in contact submitted to experiment to show the comparawith the ship's side when exploded; 2. tive disruptive force of Horsley's powder Charge exploded in the centre; 3. Offering and of common gunpowder. In each little resistance in towing. The depth of the case equal charges were used, and the torpedo below the surface can be regulated eprouvette was discharged one inch from by the speed of the torpedo vessel. A buoy is the wood and at right angles to its face. attached of sufficient displacement to support The disruptive force of Horsley's powder on the the shell at the extreme depth required, and wood was as if a solid body had been driven also to recover the shell if necessary. A safety into it, separating the fibres and tearkey is fitted, which, if properly attended to, ing a hole completely into it. The force of renders the operators safe from accidental ex- the small grain best sporting powder merely plosion, the key not being withdrawn until left a mark upon the surface of the blocks. the shell is some yards astern of the torpedo We have adduced these examples of the vessel. The charge of the shell consists of strength of this powder in order to show how about 60lb. or 70lb. of Horsley's powder, applicable it is to the purpose to which Capwhich, when manipulated under the inventor's tain Harvey has applied it. We are perfectly own superintendence, will be found equal in satisfied with the mechanical arrangements of disruptive power to at least 300lb. of cominon the torpedo itself, about which there is nothing gunpowder. a sailor could not readily understand. It has Next in importance to having an efficiently been tried in its present complete form, and has constructed apparatus is the acquisition of an answered every expectation. Here, then, we have appropriate explosive agent. In selecting an apparatus which is slowly but surely taking Horsley's powder for charging his torpedo its position as an arm of war. Other nations we think Captain Harvey has made an admir- either have adopted it or are about to do so able choice, as we know of no other substance when they have perfected it, and reports of so perfectly suitable for this purpose. Its experiments in this direction on the continent disruptive action in relation to the best gun- constantly reach our ears. We cannot too powder, volume for volume, is something like strongly urge upon our own Government the fifteen to one. Of course such a violent ex-importance of this matter. Captain Harvey is plosive would be out of the question for fire- no young enthusiast, but an officer who has seen arms, but it is admirably adapted for use some service, and has for twenty years lain torpedoes, as it embodies the greatest dis- boured to afford his country a means of keepruptive force in the least possible space. ing on a par with other nations in the matter Horsley's powder is a compound of chlorate of of naval warfare. We repeat that his torpedo potassa and gallnuts, in proportion by weight is sound in principle and efficient in practice, of three to one. The ingredients are ground and if our authorities are too slow, or are unseparately to a state of fine powder, and then willing, to recognise its merits, they must passed, also separately, through a very fine not be surprised if they next hear of it as wire sieve. The two ingredients so prepared having been adopted by foreign Governments. and thoroughly dried are blended when re- We trust, however, that we shall have to quired to form the explosive compound. The record its adoption by our own authorities, blending of the ingredients is safely and easily and we hope the day is not far distant when accomplished by passing them in a mixed we shall see the problem of the torpedo solved state through a series of horsehair sieves by its adoption as an arm of war. arranged one below the other, and set in motion. Upon the upper sieve the two ingredients are first mixed by being run together from two receptacles placed above the sieve, one containing a given weight of chlorate of potassa, and the other one-third of such weight of gallnut. As the chlorate of potassa is much heavier than the gallnuts the volumes or measures of the two receptacles are about equal. Motion being imparted to the sieves, At this point two questions will doubtless and as the two finely ground ingredients pass arise in the mind of the reader, the first, What downwards through the sieves, they will beis an efficient torpedo? and the second, Have come blended. The two ingredients thus we such an one? In answering the first ques- blended form the explosive__compound or tion we would observe that an efficient torpedo powder with which Captain Harvey charges should present a large amount of contact sur- his torpedoes. Powders in which chlorate of face, should offer the minimum resistance in potassa is an ingredient are usually regarded towing, should be equally useful by day and as dangerous. The fact, however, of cannon night, should be exploded under and in con- priming tubes, which are composed of chlotact with the vessel's bottom, and finally, rate of potassa and ter-sulphide of antimony, should be simple in construction, effective in having been prepared, stored, and used for operation, and safe in handling. To the thirty years past without accident, ought to second question, Have we such an apparatus? relieve all apprehension on that score. When we answer, Yes. Our answer is based upon treated as it should be with care, and not a careful examination of a torpedo which has improperly blended with combustibles, chlo-information on this important subject, a hydrorecently been perfected by Captain John Har-rate of potassa is practically safe. logical chart of the district of the Seine has vey, R.N., an officer with whose name our With regard to the explosive power of this been prepared, and the result of the interesting readers have long been familiar in connection powder we may adduce a few facts in the shape operations attending its production communiwith the subject. This torpedo is the result of of results of trials made to institute a com-cated to "L'Academie des Sciences" by M. more than twenty years of careful study and ex-parison of its strength as against gunpowder. Delesse. By it, the superficial and subterperimental research, and is constructed to be An eprouv tte, weighing with its carriage ranean water beds are made known, as well used against an enemy at sea, either by day 101b. 2oz., was placed on a fir plank in a per- as the nature of the strata in their immediate or night, the latter being preferred. Its move- fectly level position. The charge in each in- vicinity. Considerable difficulties have to be ments are controlled from a torpedo vessel, stance consisted of 50 grains of the various overcome in arriving at an accurate detersuch vessel being constructed for great speed, powders, and was kept in place by a small mination of the position and bearings of the and so arranged as to render the action of shot wad of thin paper. The recoil of the eprou-deeper seated beds; and it is only by comwhen bow on of little consequence to her. vette, when charged with fine grain sporting|bining the information derived frota geological The shape of the torpedo and arrangement of powder, was 9-16in.; with very fine grain researches with the evidence obtained from a slings enable the operator to diverge the shell sporting powder, 11-16in. Fine grain sport- trustworthy series of levels that sound and alongside the enemy in passing, meeting, or ing powder in a state of meal, and compressed valid conclusions can be deduced. Regarding crossing, circumstances at the time deciding by a weight of 400lb. on the square inch, gave the atmosphere as the chief agent in dis

HYDROLOGY.

T must be admitted that, however far we may have advanced towards perfection in the other branches of engineering, we are still in the infancy of our knowledge with respect to hydraulics. At certain depths in. certain localities water is nearly invariably found, and although from a geological acquaintance with the district it may frequently be predicted at what approximate depth it will be encountered, yet quite as often both the geologist and the practical hydraulician are completely at fault. The water met with in sinking a well or shaft is due generally to one of two causes, either to superficial infiltration or to the existence of a water bearing stratum. To determine these beds or sheets of water with accuracy for any particular locality, and assign to them their proper position and designation, is a labour of no mean merit. Recently, with the view of attaining more thorough and reliable

nature.

persing water over the surface of the earth, was obtained for the city of Paris, and which they were effective. The iron distributed it is manifest that of all the rain it discharges in the present is conducted to it by the aque- about a wooden ship acts on the general sphere upon a given locality, a certain proportion is duct of Arcueil. Particular care has been of magnetism by condensing it; consequently carried away by the rivers directly into the taken to accurately represent upon the hydro- on the magnetic needle, according to the posi sea. M. Arago, many years ago, calculated logical map the first subterranean waters met tion and distance of such iron with respect to that in the valley of the Seine this proportion with in sinking, as they are those supplying the magnetic needle, and also according to its was rather under one-third of the total quantity the ordinary wells. Sometimes the wells tap general mass. Now, if this mass had been disthat falls in that district. The remaining two-water which really flows at a lower level, but tributed symmetrically on two sides of the comthirds are therefore accounted for by evapo- which springs violently up to a much greater pass, as it might have been had it been possible ration and infiltration, neglecting the small height. A register placed in each well marks to place the binnacle exactly amidships, it quantity that is absorbed by plants, and ren- the height to which the water rises, and, more- could have been more easily compensated for, dered otherwise conducive to the necessities of over, indicates the stratum in which the but as the binnacle must be placed close to the sinking is arrested. By means of the hydro- stern the distribution was necessarily very timeter the hardness of the different waters is unequal. The way that Mr. Barlow compen ascertained, and the number of degrees re- sated this unequally distributed disturbance corded upon the chart. From this hydro- was by placing the compass within the sphere logical plan of the district of the Seine, the ofa much more powerful but symmetrically disdirection and nature of the movements of tributed disturbing influence. As the condensthese two descriptions of water beds and ing power of iron acts on a magnetic needle their mutual relations are distinctly perceived; in proportion to the square of its distance from their form, position, and depth at which they it inversely, it is easy to overcome the power will be encountered are likewise determined. of a large mass at a distance by a small mass The density of the water is also indicated; but placed close to the needle; therefore he placed the chief point gained is the facility the chart a disc of iron close under the needle whose offers for ascertaining the conditions existing symmetrical condensing power was so great that between these waters and the geological for the unsymmetrical power of the iron in the ship mation of the ground. Not until we become was as nothing to it. better acquainted with the internal economy of nature respecting the distribution and movement of the vast stores of water in her possession, shall we be able to utilise them to a maximum, and derive those advantages which we have a right to expect, and which they are well calculated to afford.

By carrying an extensive system of levels throughout all the wells and other spots where water was reached, a number of points in the upper surface of the water beds were thus obtained and referred to the same datum, the mean sea level. The difference of level would enable the various water beds to be distinguished from one another, and classed accordingly; and as the character of the sub-strata of the environs of Paris is thoroughly known from the geological chart presented to the Academy by M. Delesse, it becomes possible to determine their exact position and extent. The name of beds of infiltration has been bestowed upon those sheets of water communicating directly with water-courses, and the fluctuations of which they follow with perfect fidelity. They exist in the permeable strata surrounding them, and show a strong development along the route of the Seine and the Marne. On the other hand, the subterrancan waters have their origin upon the impermeable strata, and are distributed in close conformity to the irregularities and undulations presented by them. Their most prominent appearance is to be observed in the clay beds of Beauce, the green marls, and the plastic clay. When once a certain number of points have been ascertained in a subterranean couch or stratum of water, it can be represented by plotting a series of horizontal curves, which is performed in the chart; thus defining the limits, the form, and the upper surface of the stratum with considerable accuracy. In the delineation of the bed of infiltration of the Seine, the horizontal curves are represented by undulating lines nearly parallel to one another. They are disposed symmetrically along each bank, and are connected with the superficial stratum of the river. The level of the bed is higher than that of the Seine itself, and continues to rise the farther it recedes from its boundary; and is therefore fed by the waters descending from the hills which form the valley through which the river winds. In the islands of the Seine and the Marne there are also waters of infiltration, giving rise upon the chart to concentric horizontal curves nearly parallel to the contours of the land, but displaying a slight slope towards the central portion and dipping in the contrary direction towards the shores. They occupy a far more extensive area than the other waters, being principally distributed over the valleys of the Seine and the Marne, and, moreover, extending up the sides of the permeable hills. It is from this source that all the wells are supplied.

COMPENSATION FOR LOCAL DIS-
TURBANCES TO THE MARINER'S
COMPASS.

When ships were wholly built of iron insteadof wood, at the first sight it would appear that the cause of this local disturbance would be only intensified; but in an enormous degree, as the effect of the mass of iron in an iron ship would be almost infinite in comparison with the effect of the iron fastenings of a wooden ship, but of the same nature, and so it would have been had it not been for another property of ordinary iron-that of acquiring permanent magnetism. This power has been found to be so great that it overpowers the power of condensing the general sphere of magnetism; HERE is no instrument of greater im-doubtless the one modifies the other, but the portance in navigation than the com- nett result felt is that of the permanent magpass, and in proportion to the reliance placed netism of the ship. Of course the iron fastenupon it is the danger, if any error should have ings of the wooden ship had the same property, crept into the result indicated by it. Ship- bnt then they were in detached pieces and wreck and loss of life have been the result of placed at all angles to each other, so that the such error. Since the first invention of the permanent magnetism of each tended to compass by the Chinese there has been no neutralise that of the whole. As an example time when the rectification of such errors have the "Northumberland" may be cited. As to the been of so much importance as now, and there demagnetisation of such a ship we will not has been no time when the disturbing causes say that the idea is chimerical; but at any have been so great and so difficult to over-rate, from all accounts, we may say that it come. When ships were wholly built of wood has not been successful, and also that we have the disturbances were grave enough to produce not much faith in it. It is a grave question, many disastrous shipwrecks, consequently as troublesome as fouling and corrosion, and sufficient to excite the attention of scientific like it has been treated empirically. As at men to devise some means for compensating present treated it is a never ending attempt at them. Many were the expedients devised correction, always being corrected. Formerly without effect, such as placing magnets in the local magnetic disturbances in wooden various positions to counterbalance those dis- ships caused considerable trouble, but was turbances, and it would appear that these devices eventually satisfactorily settled, as no doubt were tried without due consideration of the the magnetic disturbances in iron ships will be. nature of the disturbing causes. In wooden No doubt this is a more difficult problem than ships these disturbances were caused by the that was; but still of the same nature. That various masses of iron necessarily used for the was a case of magnetic conduction and confastening of the timbers and planking, and it densation; but this is not only that but also should have been considered that iron generally a case of magnetic polarity. The irregular does not act as a magnet, but simply as a con-condensing power of the iron in wooden ships denser of the general magnetic sphere of the was overcome by a greater condensing power earth. Now as ships are much longer than in a symmetrical disc of soft iron. In iron ships they are broad there would be necessarily an we have to overcome the polar magnetic Above these waters the others are generally accumulation of that condensing power in a sphere of the ship: that is, to render the space found, lying upon the clay of Beauce and the line with the keel of the ship; consequently wherein the magnetic needle of the compass green marls, so that their limits are ascer- the only position in which this disturbing has to act perfectly neutral to local influences. tained with comparative facility. The case, cause would be of no effect would be when This thing can be done, we think, or at least however, is otherwise with the waters of the the keel of the ship ranged due north and has been done in a certain way, by Mr. plastic clay, which invariably cut those of infil-south. Faraday, and described by him in his re tration at a small angle in such a manner It will be seen that the disturbances to be searches. The only difficulty is the adapting that the line of their intersection can only be dealt with ranged through two quadrants on of his experiment to the present problem. He determined with approximate accuracy. each side of the meridian on which the ship has shown that if a small cubical chamber be These waters supply the wells of the south of happened to be placed; that is, as to the cause made by placing the like poles of six square Paris, those of the north-west, and those in the of disturbance existing in the ship. The bar magnets together, inside that chamber will vicinity of Mount Valérien. Upon the sum-general variation of the earth's magnetism and be a perfectly neutral space to all local magmit of the hills and plateaux surrounding the position of the magnetic pole, though they netism; that is, to all local magnetism Paris, we come upon the waters of the green can be calculated and known, yet in the whichis much weaker than the power of the marls which supply a large number of sources. various positions of the ship, they very much magnets employed. The chart demonstrates clearly that nearly all complicate this local disturbance. Had these The same effect is produced when four magthe water falling upon the plateau of Villejuif things been duly considered, it would have nets only are used, being placed horizontally, flows rapidly away underneath the surface of been foreseen that no arrangements of per- so that four sides only of the cubic space are the ground towards Rungis, whence they are manent magnets could possibly rectify these occupied by the like poles of four magnets. carried off by a steep incline, and constitute errors. Mr. Barlow was the first to see this, The centre of this space is also perfectly neu the source from which in the olden time water and the means he devised were as simple astral. It is not necessary that this neutral