allows the water to pass to the boiler, but prevents its return to the cistern.

In the engravings the steam valve is open, and the water supply valve shut, in which condition the water, by its gravity, descends through the feed pipe a into the boiler. As the water is lowered in the cistern the float falls with it, moving the float wheel h, and causing the stud n to turn over the tumbler lever 1, which acts upon the quadrant p, which shifts the levers q and r so વ્ as to shut the steam valve and open the water supply valve to the cistern and supply it with water; and when the float has risen to a certain height, the stud o reverses the tumbler lever, which shifts the quadrant, causing it to reverse the levers 7 and r, and shut the water supply valve and open the steam valve, when the water descends as before, which operations are continuous and self-acting.

The great advantage of placing the water supply valve on the top of the closed cistern is, that when the valve is opened the steam and air rushes through the supply pipe to the supply cistern or water, and by becoming condensed, allows the supply water to return, passing through the holes of the distributor plate, when a vacuum is speedily obtained in the closed cistern, by which means, when required, water can be raised from a depth of about twenty feet.

In Fig. 4, c represents part of the rod of one of the valves, having in it a number of grooves d. When the apparatus is working the grooves hold the water or condensed steam, so as to form a water lute, and prevent any escape, and enable the rod to move freely in its guide. To the float wheel is attached an additional stud or pin e, connected to which is a rod f, on which are two adjustable collars g for working the lever h of the register or counter b, so that the volume of water at one feed being known, and the number of movements denoted by the register in a certain given time, the exact quantity of water fed to the boiler can be calculated with exactness.

pulley keyed to its lower part, and is free to rise and fall to regulate the distance between the stones. The lower stone is suspended from the centre of the frame through which the vertical shaft passes. Motion is communicated to the upper stone through a pulley keyed on the vertical shaft; the grain is fed by a hopper on to a bowl, from whence it is driven by centrifugal action between the mill-stones. A double case is placed on the hopper, and prolonged close to the bowl, and air passes in from a ventilator through a pipe provided for the purpose. The shaft for the ventilator is the same as that for the exhauster, so that they both revolve together. The ventilator and exhauster shaft is driven by a belt passing round a pulley fixed thereon, and round another pulley on the horizontal shaft supporting the upper stone. Springs may be applied under the frame carrying the lower stone, and the lower stone may be connected to the frame, from which it is suspended by a conical cap fitting over a conical centre formed on the frame. Friction balls or spheres may be placed for the cap to rest upon. The accompanying engraving shows in sectional elevation so much of a mill for grinding corn as will be necessary to illustrate the manner in which this invention is carried into effect.

A is the grain hopper; B is a second hopper, which may in some cases be dispensed with; C is a cross beam for regulating the supply of grain, adjusted by a rod through one of the hand wheels CC; D is a bowl or cup in which the grain falls from the hopper, and from whence it is driven by centrifugal action upon the lower stone M; E is a collar keyed in the top of the vertical shaft II. This collar is formed with two arms or trunnions a a, which drop into sockets cut in the ring F This ring F is also formed with trunnions, which are received in sockets made in the ring G, the back of which is embedded in the upper stone I. The vertical shaft H passes through the frame L, it is driven by the pulley N, and imparts rotary motion to the upper stone I. A casting is formed with two sockets and two arms, or trunnions,

which latter are embedded in the lower stone M.

ING CORN AND OTHER GRAINS.

C

N

M. BRISSON, of Orleans, France, has just patented in this country certain improvements in mills for grinding corn and other grain. The first part consists in suspending mill-stones from their central parts, and in the application of this mode of suspension to the lower as well as to the upper stone. The two stones suspended in this manner are free to perform similar oscillations; the upper is the travelling or working stone, as shown, but this arrangement may be reversed, that is to say, the lower may be made the working stone. The invention also consists in the application of a ventilator in combination with an exhauster to mills for grinding corn and other grain. The upper stone is connected to a vertical shaft, through a collar keyed to the shaft, and carrying two arms or trunnions, these take into another collar also carrying other arms or trunnions which are inserted in two semicircular grooves, formed in a collar fitted on the stone itself. The vertical shaft passes through a frame; it is driven by a

with two sockets or apertures, into which two trunnions or arms in the frame L enter. This method of connection allows of free oscillation to the stone M, and of its yielding to the motion of the upper stone; P is a drum or case enclosing the stones. Air is supplied to the stones by the fan R, which causes it to enter through the tube which extends from the case B down to near the bowl D; S is a white metal tube communicating with the fan R; X is another fan separated by a division plate from the fan R, but keyed on the same shaft. The fan R draws in air at V, and drives it out at Q; the fan X draws in air at U, and discharges it at T. The fans are driven by a belt passing round a pulley g' on the fan shaft, and round a pulley g on the vertical shaft H. The fans are supported in a frame Z, bolted to the side of the drum or case inclosing the stones.

HOROLOGY.

WE have on previous occasions made comments referring to the above subject, with the view of impressing on the chronometer clock and watch manufacturers of England the importance of taking active measures for organizing some more efficient plan or system than the present of conducting the manufacture of their respective productions; we conceive this to be quite practicable, and, therefore, feel called on to express our satisfaction in noticing the progress made by the British Horological Institute, in disseminating scientific and practical information through the medium of the Horological Journal; this is manifestly a step in the right direction, which we trust may lead to the eventual accomplishment of so desirable an object.

The last and present month's numbers of the Journal (29 and 30), contain reports of an important paper read by Mr. J. F. Cole, vice-presi

dent, in further illustration of the diagrams presented by him to the Institute, relating to his former lecture on the general principles of timekeepers, the chronometer and detached lever escapements, and his improvements thereon.

The paper and subsequent illustrations by Mr. Cole, at the discussion meeting, contained matter of especial interest to watch manufacturers, as developing fundamental principles whereby to determine with precision the proper angles of lever pallets for producing either long or short arcs of pallet motion, and containing also practical rules for giving to the lever and roller, in either case, their proper proportions.

FIG. 1.

escapement entire, the pallet angles in which are The above diagram, Fig. 1, represents a lever determined by an original adaptation of a scale of degrees, the principle of the scale applying correctly to pallets scaping over three teeth, 15 being the number of teeth in the wheel, as generally employed. In this diagram one of the wheel-teeth of a pair, with arms of equal length, such pallets is at rest on the inner locking of the second pallet being said to be "in circle," and in order to give the angle necessary for producing 12 degrees of pallet motion, by the traverse of the wheel-tooth upon the plane of impulse, a base line o, o, is drawn from the delivery point of the second pallet through the centre of the pallet axis; from the same delivery point another line is drawn to the right of the axis at an angular distance of 24 degrees, as marked in the diagram; this is called the angle of divergency, and the line forming it, cutting across the intended pallet, gives the required angle for producing 12 degrees of pallet motion in one direction, conditionally with the centre being placed at a certain point outside the periphery of the wheel, as shown hereafter. This second pallet angle being now correct, the first pallet angle is formed so as to produce, by the action of the wheel teeth, equal hold on each locking, and to allow the teeth to escape with no more than proper freedom; by these means the angle 12 degrees of motion in the contrary direction is of the first pallet impulse plane for producing at once determined, and this done, it will be found that the face line of the impulse plane thus formed will be direct to some point on the second pallet, 24 degrees, which process needs no repetition, as given by the previous operation, from the scale of the direction of the first pallet plane being known therefrom, is a ready and sufficient rule for determining the angle of the second impulse plane, for producing in future pallets 12 degrees of motion from the locking points in either direction, and if two degrees be allowed for the hold on each locking, there remains 10 degrees of virtual impulse on each pallet.

It will be observed that the number of degrees in the scale set out as the angle of divergency, is double the number contained in the arc of motion produced at the pallets, and this rule is found to operate correctly for greater or less arcs of motion than the 12 degrees here explained for pallets

The above diagram, Fig. 2, exhibits Mr. Cole's method of determining the place of the pallet centre of motion; this is done by laying down on paper, or on a prepared metal plate, a circle of any diameter representing the intended lever escapement wheel, of any number of teeth decided on; in this diagram the ordinary number 15 is adopted, though any other number would do equally well for the purpose; the circle being correctly divided into 15 equal parts, a radial line is drawn from the wheel centre c, passing exactly through one of the division points, each representing the point of a tooth, and the line extending to the point a, an equal distance outside the circumference of the wheel circle; before proceeding further, the number of teeth to be scaped over by the pallets

must be determined.

Three or more teeth may be embraced by the pallets, but as three is the customary number that number is used here, the pallets therefore embrace three teeth and two spaces, reckoning these teeth and spaces backwardly from the first radial line and point, as the place of the inner or second pallet locking; the third space therefrom must be divided by a point placed exactly midway between the locking extremities of the two teeth forming that interval, and through this subdividing point (now the place of the first pallet locking) a second radial line is drawn from the wheel centre c to the point b, equi-distant as before, beyond the circumference of the wheel circle.

It will also be observed on the diagram, that the wheel-centre c, and the two points a and b (in reference only to 15 toothed wheels), form an equilateral triangle, the wheel being 15 is divided again by the alternate action of the pallets, into 30 equal parts, giving that number of impulses in each revolution; five of those parts are included within the radial lines, forming two sides of the triangle = 60 degrees, which multiplied by 6, completes the circle of the wheel and serves to show, as will be seen, how naturally this geometrical figure is found to harmonize with all points essential to the true development of the principles of this class of escapement; when 15 toothed wheels are employed, the sides of the triangle are equi-distant from the pallet centre, but not so for any other number.

From the locking point on the first radial line ca another line is drawn to b, the opposite apex of the triangle, thus forming a true perpendicular to the radius c a, as a tangent to the wheel circle, and from the locking point on the second radial line e b, another line is drawn to a, the second apex of the triangle, as a perpendicular to the radial line e b, also a tangent to the wheel, and at the point where the two perpendiculars intersect each other, will be

each holding 200 gallons. The following were

the true place of the pallet centre of motion, the triangle therefore being the simplest means of the results:producing the rectangles explains the motive for using it.

From these remarks it will be evident that any change from this mechanically proper position of the pallet centre thus determined can only be productive of defects at the lockings: these consist in diverting the rectangular direction of the wheel force, which may be preserved on the inner locking by allowing the whole defect to fall elsewhere, as it would do by moving the centre forward on the line b d, to a position equi-distant between the outer locking corner and the delivery point of the second pallet, thus preserving the rectangular bearing of the wheel-tooth on the second or inner locking; by this displacement of the centre, the whole defect is thrown on the first or outer pallet locking.

In illustration of this, it is found by careful measurement of a correctly-made drawing on a large scale, where the degrees are accurately set out, that the proper geometrical distance of the pallet centre outside the periphery of the wheel circle is exactly one-fifth part of the chord of five teeth of the wheel from point to point, and as pallets are usually made, the distance or pitch of the centre is sometimes less; admitting this, the ultimate effect of the draw on the lockings will be sufficiently correct, provided the locking angle on the first pallet be made stronger, to suit the altered position of the centre on the line bd, as evidenced by the effective action of well-made pallets generally employed in the manufacture of lever pocket watches.

for determining the centre for pallets of any arc The rectangular method shown in this diagram of motion is not given as an arbitrary rule, further than as relates to securing equality of hold and uniform resistance on both the lockings; but the advantage in those respects cannot be made available without departing from the customary mode of making ordinary lever pallets; in such, the centre is placed at an equal distance between the outer extremities, leaving arms of equal length. Contrary to this, the pallets shown in Fig. 2 have the effective force of the wheel in giving impulse arms of unequal length; hence it may appear that to the balance would be unequal also. This though true in regard to simple leverage is not so in the complex connection with diagonal planes, as the difference of leverage on the long and short arm admits of perfect equalisation, by giving to the first impulse pallet a convey surface instead of a plane; by this simple alteration the effective power and pallet motion produced will be exactly equal in both directions, and the locking resistance on both sides will also be equal, as both locking planes traverse the same circle.

In this diagram, the arc of pallet motion is 15 degrees twice multiplied by the lever and roller proportions, which makes the balance are 30 degrees, as fully detailed in No. 30 of the Journal; but in diagram Fig. 1 the pallet are of motion being 12 degrees is multiplied by the lever and roller proportions as three to one, making the balance are 36 degrees. In either of these contrasted modes the mechanical effect would doubtless be alike satisfactory, as the lesser balance are of 30 degrees, and consequent lower tension of the balance spring, offers less resistance to the long are pallets; and provided also the motive power, the weight of balance and strength of balance spring, be so proportioned as to produce one turn and five-eighths of vibration; beyond this, the ultimate time keeping results will depend on the completeness of the general mechanism, and the care observed in making the final adjust. ments, whether for lever pocket watches or timekeepers of whatever construction.

ROBERTS' PUMPS.

On Wednesday and Thursday, the 6th and 7th instant, some experiments were tried at H. M.'s Dockyard, Portsmouth, on board the Rinald, to test the capacities, &c., of Roberts' against Downton's pumps, the water being pumped into tanks

FIRST DAY. 1st time from Wing Cock 2nd 3rd nold....... 1st time from Hold....... SECOND DAY. 2nd

Wing Cock

Total.........

Difference of Strokes and Time

The same four men worked the pumps in each

case.

The time occupied in taking off the air chamber, the valves out, replacing them again, and fetching the water, was by Roberts' pump 42 seconds, and done by one man; while it took 12 minutes to take the cap off Downton's, lift the buckets so that the valves could be seen, and get it again in working order, and took 6 men to do it. The above trials were witnessed by AdmiralSuperintendent the Hon. G. Grey, Mr. Moody, and Mr. Sturdee, the Acting and Assistant

Master Shipwrights, Mr. Murray, chief-engineer, and the principal officers of the ship, &c., and confirm the trials made in 1857, at Woolwich, viz., that Roberts' 5 in. pump will throw 40 per cent. more than a 7 in. Downton, and that the valves of Roberts' pump can be got at instantaneously.

ROYAL GEOGRAPHICAL SOCIETY.

ON Monday evening last this Society was held. president, in the chair. business of the evening,

a crowded meeting of Lord Ashburton, the After the preliminary

The President said, the geographical features connected with the proposed North Atlantic Telegraph quarter of the globe, who he hoped would give their scheme were already before the public. They had amongst them experienced travellers from every assistance in correcting, amplifying, and illustrating, the papers which had been read at the previous meeting. The subjects peculiarly within the province of the Society were the geographical features; they were not engineers nor electricians to judge of the power of the electric current to pass from one quarter of the globe to another; they were not members of Parliashould be afforded to men who had devoted themment, who were to determine what aid or facility selves to this great enterprise; nor could they judge between the many plans brought before the public. They were to judge of the geographical features, and it was with hope of much instruction and knowledge that he would call upon the gentlemen who would address them on the subject.

interest in a deputation to Lord Palmerston to get Sir Edward Belcher, R. N., said he had taken great the scheme carried out, and he was happy to find that nearly all the arguments then used had been fully realised. He had thought, in the first instance, and it had been proved, that there was a connecting bank between England and the Faroes, and between Iceland and Greenland. He was glad to find the difficulties in regard to the reefs, which it was said would entirely prevent any cable being laid across, had vanished, and they were rather a help, in prelarge quantities of shells at the bottom. They thought venting the ice from coming down. He had found nothing of bringing up a hatful at a time, and he had a very handsome collection of them in his possession. He thought if proper instructions had been given by the Admiralty more soundings might have been taken. He described a plan which he had found to answer in taking soundings at a great depth, and expressed his satisfaction at those taken by Captain M'Clintock.

Mr. Miles in concurring in the advisability of running a wire in the direction proposed said, they had no meteorological observations in Iceland for the last 50 years. He did not think it was so cold there as was commonly supposed. The absence or presence of trees be thought did not indicate the coldness of the country. It was well known that on the coast of Norway trees attained a pretty good size, although the weather was more severe than in Iceland. It

struck him, when one of the speakers on a previous occasion said that the Lake of Reikwick froze to the depth of 18 feet thick, there was some mistake. From his own experience he had known it sometimes freeze to 18 inches, and he had known it sometimes to freeze no more than 2 inches during the whole of the winter, which was a proof that the climate was not very cold. Captain Sherard Osborn, R.N., said he would not at tempt to say anything as to the practicability of the route, inasmuch as the distinguished travellers and navigators, who read their papers at the last meeting, had given them sufficient authority to say that there were obstacles on the route undoubtedly, but that all those obstacles were surmountable. Touching upon the soundings, he would call their attention to the agree able fact that the entire line of soundings show that there is no depth greater than 1,000 east of longitude 30 west on the proposed route. With regard to the Labrador coast, the principal difficulty was in carrying the cable within the 150 fathoms of water, so that it might not be exposed to the action of the icebergs. He was sure that Aretic men were nearly all agreed that 150 fathoms would be about the maximum draught of any iceberg, so that the chief object to be secured in placing the cable was to push the 150 fathom mark as near into the coast as possible. They would remember that Sir Leopold M'Clintock had said that he would like to have a more accurate survey of the Labrador coast so as to carry the deep water a little closer. If they looked at the map they would see 1,190 fathoms carried, just to the north of Hamilton Inlet, very close into that little projecting point, and they had every reason to believe that the Bank of Newfoundland-they might call it so, although it extended a long way up the Labrador coast-deepened suddenly there. As far as one might speculate upon the question, he had no doubt that a more accurate survey would lead to the obtaining of such information as would give them a channel leading close into the Labrador shore. He would propose, that the cable there should open out and form, say, half-a-dozen strands running into the shore at certain distances from each other, so that if a berg drifted down and happened to pick up one, it would not pick up all the rest, and by that means the cable in the deep water would be at all times safe and recoverable by following out these strands. There was one feature that struck him particularly, and on which he wrote to Captain M'Clintock. No man

would dispute that bergs of ice sounding the bottom would rip it up, just as a plough would a ploughed field. It occurred to him (Captain Osborn) that if that bank was thus ripped up by the flocs of ice, there would be hardly any animal or vegetable life, it would bea kind of subterranean desert. Sir Leopold M'Clintock was continually dredging there, and in his report he stated, that he found shells, fish, delicate corals, and creatures which could not live at the bottom of the sea if much disturbed by icebergs. That was a question he did not pretend to solve, but the fact was very curious as showing that bergs could touch the bottom without sweeping everything before them. He was sure that every geographer would be interested in the fact he was about to mention, for it related to Sir John Ross, who stated that in his voyage in 1818 he brought up mud from 1,050 fathoms, the deepest soundings ever obtained at that time; and in the mud were shells and fish. So to that old navigator they owed that the fact of animal life in great depths had been discovered. As they were talking the other day about the difficulties with regard to the intense cold, and the aurora borealis affecting the telegraph, he remembered that a few seasons ago, Captain Kellet and Captain M'Clintock were beset in the ice in 744° north, and they communicated with each other by telegraph from ship to ship.

That (744) was a long way in the Arctic zone, and the cable, the practicability of which they were at present discussing, would lay a long way without it. That telegraph was at work throughout the whole winter, and was not in any way affected by that terrible bugbear, the aurora borealis, nor by the intense cold experienced so far north. (Applause.) Mr. John Ball said, that while acknowledging the importance of all that had been achieved, and believ. ing in the practicability of the proposed northern route, they ought not to underrate the obstacles that remained, which were many. The description given of the interior of Iceland showed that there was an extensive desert to be traversed by the horses, and no timber to form the piles with; nor did he think the difficulties on the sea coast of Labrador had been suffi. ciently considered, and recommended taking the cable to the strait of Bell Isle.

Sir R. Murchison was prepared to accept as conclusive the opinion of the Arctic navigators who had pronounced in favour of the scheme. He had no personal interest whatever in the undertaking, yet he

must allow that the promoters had put their case very ably before the public, and that gentlemen associated with the other cables must admit that it had been done in a very clear and candid manner. Sir Roderick concluded by acknowledging the very valuable assistance which had been accorded by the Danes to the present undertaking.

Dr. John Rae said in reply to Mr. Ball as to the inland difficulties of Iceland, that during his journey he never wanted grass or water for his horses. They rode on an average 30 miles a day, and the journey was made in 13 days without any impediment. The horses were in the habit of carrying 200, and would therefore be able to carry the piles to any district where they might be required. The other more

southern route across the island was still casier.

MEETINGS FOR THE WEEK. Mox.-Medical, Lettsonian Lectures, at 8.30 p.m.

before stated, 9,333, and the co-efficient of perfor mance, with reference to power, is 250, assuming the consumption of coals to be at the rate of 3lbs. per indicated horse-power per hour, would require to be enlarged to 15,000 tons to attain the speed of 18 knots per hour, retaining her present armament of 1,500 tons, and her present steaming endurance of 6 days at 14 knots per hour. Mr. Cheverton, in his letter in your Magazine of the 25th ultimo, admits the foregoing deductions, but he remarks as follows;-" Mr. Atherton, I think, puts the matter in a worse light than is necessary, inasmuch as though it may be requisite to have an increase in size from 9,000 tons displacement to 15,000 tons, it is not required that it should be by an enlargement of the exact model of the Warrior. Would it not be better to effect the enlargement in a future ship in length alone ?"

Mr. Cheverton then adopts, as an axiom theoretically applicable to the case of the Warrior, in adynamic point of view, that by enlarging the ship in length alone, and retaining the same midship section, the

London Inst., "On the Progress and Power of ship so enlarged or elongated from 9,000 tons dis

Music as Exemplified in Lyric and Dramatic Representations," by T. Pittman, Esq.

placement to 15,000 tons, will require no additional United Service Inst., "Swiss Targets and Rifle power to attain the given speed of 14 knots per hour; and on this assumed axiom he bases his tabular stateRanges," by J. Latham, Esq., at 8.30 p.m. ments and deduces the results published in your MAGABritish Architects, "Description of Mons. Mariette's Excavations at Ghizeh and Saccara;" ZINE of the 25th ultimo, so greatly in favour of his elon"Some Observations upon the Domestic Arch-gated ship, as compared with the enlarged ship on the tecture of the Ancient Egyptians as Existing among the Present Arabs;" and "An Account of Catacombs at Alexandria Recently Discovered," being notes made during a recent visit by Thomas L. Donaldson, V.P., Fellow, at 8 p.m. TUES.-Inst. Civil Engineers, "On the Results of Trials of Varieties of Iron Permanent Way," by Mr. Francis Fox, M. Inst. C.E., at 8 p.m. Zoological, at 9 p.m. WED.-King's College, Prof. Tennant, F.R.S., "On Geology," at 9 a.m.

Warrior type. I have merely to say that experience does not justify the arbitrary adoption of any such axiom; doubtless experience has shown that a ship may be so short and bluff as to admit of its being beneficially lengthened; experience has also shown that a ship may be so long and fine as to admit of being beneficially shortened. But on the axiom propounded by Mr. Cheverton, if admitted as of general application, all we have to do is to make the midship section small enough, the length of the ship long enough, and the surface slim enough, in order that a power as small as we please may propel a ship, or sea serpent," of any size we like, at a given speed. Geological, I., "On the Coincidence between the An axiom leading to such conclusions cannot be adStratification and Foliation of the Altered Rocksmitted in the theory of naval architecture. of the Scottish Highlands," by Sir R. I. Murchison, F.R.S., V.P.G.S., and A. Geikie, Esq., F.G.S.; II., "On the Relations of the Strata of Some Portions of the Scotch Highlands (South of the Caledonian Canal) and of the North of Ireland," by Professor Harkness, F.R.S., F.G.S., at 8 p.m.

Society of Arts, "On the Alpaca and its Introduction into Australia," by Mr. George Ledger,

at 8 p.m.

THURS.-Antiquaries, at 8.30 p.m.

Royal Soc., at 8:30 p.m.
Chemical Soc., at 8 p.m.

FRI.-United Service Inst., "The Survey of Rivers," by Captain R. Collinson, R.N., C.B., at 3 p.m.

Correspondence.

ON THE SPEED OF SHIPS.

TO THE EDITORS OF THE "MECHANICS' MAGAZINE."

Woolwich Dockyard, Feb. 1, 1861. GENTLEMEN,-Until the last few years the relative character of ships, as respects their dynamic merits, was a matter of opinionative presumption, not based on any numerically comparative results such as are obtained by the now recognised co-efficients of trial performance and of economic duty. This system of numerically comparative test is now producing remarkable effect in steam-ship economy; and it is for the purpose of popularising this system, and in the hope of protecting it from being vitiated, that I occasionally appear in your pages; but, to return to my subject,-the higher the co-efficient the better the ship dynamically, and the co-efficient of performance of a steam-ship of given type of form being once practically determined by trial, or admitted as determined, as in the case of Warrior, it is then regarded as scientifically legitimate to adopt this co-efficient for determining the mutual relations of displacement, power, and speed, that may be expected to be realized under similar circumstances of trial by a vessel of the same type. Such is the principle on which I based my remarks on the Warrior, published in your MAGAZINE of last week, showing that the type of Warrior, of 9,000 tons displacement, of which vessel the assumed co-efficient of duty, with reference to coals, is, as

I am, Gentlemen, yours very obediently, CHARLES ATHERTON.

"REWARDS OF INVENTORS." GENTLEMEN,-In your very common-sense article on the "Rewards of Inventors," you make one error. You say, "If such a rule had been in existence, probably Messrs. Adams and Richardson, after making a profit of £34,000 by their patent, would not have made application for its extension."

No real profit or any fraction of such profit has been made by me. It was profit made and divided by the patent had passed, as very common with patents, Permanent Way Company, into whose hands the after the inventor has done his work. This company applied to me for the use of my name in the application, and for which, if successful, they were to give me the lion's share in all future profits. I presume they thought that the fact of an inventor who had obtained nothing would exercise some influence on the decision of the Judicial Committee, or they would scarcely have proposed this. Before agreeing to their proposition, I consulted several of the foremost railway engineers, by whose counsel I agreed to it. I was subsequently laid up with dangerous illness, and it was only a day or two before the application came on that I became aware of the company's statement, that their profits during the term of the patent were £34,000, and that they estimated the annual savings to be about £450,000 per annum on the fished lines of railway; or about £6,000,000 in fourteen years, apart from the question of safety and running at increased speeds. If this is so, the profits to the company are under three quarters per cent. of the total gain to the railway community. Of the facts of these statements I know nothing, but assuredly it is a grievance of no small consequence to the body of inventors, that there is no fixed legal standard by which to appreciate their value, instead of leaving it to the arbitrary decision of a changing body of men whose unimpeachable integrity is no guarantee for their exact appraisement of the real value of inventing brains, without any fixed principle being laid down as a basis for calculation.

The solitary consolation is, that it is only by a succession of individual martyrdoms that public opinion is at last drawn to the redress of grievances. With the "process of the suns," English inventors, to whom it is mainly owing that England is not as China-a non-progressive country-may hope to be rescued from the mero motu arbitrary will, which grants or prolongs patents as a favour, and not as a fixed legal right; and also some effective care of property that shall make patent justice attainable by the poor man, instead of a mere appanage of the long

purse. It is not many years since an actor was in law a "vagabond" save as a "servant of majesty," and the inventor is ever regarded as a "schemer," and not a follower of honest industry till "thought has wedded fact" in the form of a large banker's balance. I am, Gentlemen, yours faithfully, W. BRIDGES ADAMS.

NEW FORM OF BAROMETER.

GENTLEMEN,-I take the liberty of sending you a form of barometer I have devised, having advantages not possessed by the ordinary tube. In the common barometer, the mercury rising in the smaller tube prevents accuracy in proportion to its weight. But in the accompany ing figure the end of the tube being coiled round in a plane, the surplus mercury is horizontal; so that the column of mercury is an absolutely correct measurer of air pressure, and not of air and mercury combined.

31 us

30

Ins

GENTLEMEN, Observing from time to time in your valuable journal several articles and descriptions of the construction and working of ships' pumps, particularly of late, in our navy, it would be of great service to me, to several of your readers, and of importance to the shipping world, if some of your very able contributors would say "What a ship's pump should be? what are its chief requirements, and the great object to be kept in view in its construction for efficiency?"-as the two pumps now occupying the attention of the Admiralty are known to be the most complicated before the public-and why a well-known and tried pump, Massie's, in the service, should be

cast to one side.

"A PUMPER."

MR. COLLINS ON ELECTRO-BLOCK PRINTING.

GENTLEMEN,-I do not know whether the follow

NOTICE.

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Our Weekly Gossip..

THE MECHANICS' MAGAZINE has from the first paid particular attention to the magnificent North Atlantic telegraph enterprise. We heralded and hailed Sir Leopold M'Clintock's expedition, and immediately on his return we gave our readers the benefit of his and his colleagues' researches. And as the subject is now deservedly exciting public attention, we give this week, with a report of the discussion on the papers read before the Royal Geographical Society by Sir Leopold M'Clintock, Captain Allan Young, Mr. Tayler, Dr. Rae and Col. Shaffner, a map in which is accurately named the route of the Bulldog expedition. The depths of the soundings from the Orkneys to the coast of Labrador are carefully given; also the depths of the soundings for the Atlantic telegraph route, by Comr. Dayman in 1857. All who are interested in the information we have given since Sir Leopold M'Clintock's return may find it in Nos. 103, 104, 105, 107, and 108, of the new series of the MECHANICS MAGAZINE.

sometimes hope for victory without any other quality of generalship. His men may never have to dare death in the imminent deadly breach; he may look on the "forlorn hope" as a coarse and now obsolete instrument of success. All he has to do is to calculate distances, to measure the strength of guns, the weight of projectiles, the explosiveness of compounds.

The

Messrs. J. Reid and Co., of Port Glasgow, have just completed a steam train, on Bourne's patent, intended has been built for the Oriental Inland Steam Navigafor the navigation of the Ganges. The train, which tion Company, consists of a steamer and five barges, and is 930ft. in length over all, 30ft. beam, and 8ft. depth of hold. The steamer is fitted with engines made by Fawcett of Liverpool, and having surface condensers, superheating apparatus, &c. The engines are on the double cylinder principle, high and low pressure, and the boilers are capable of working up to a pressure of 100lb. on the square inch. machinery is 400-horse power nominal, but can work to upwards of 1,000-horse. At the bow of the steamer is an apparatus for manoeuvring or steering the train, and each barge has a helm, but it is little used, not being generally required. The barges are attached to each other by hinge-joints, which enable the train to turn easily into curves in following the windings of a river. The train, which is built of iron and is very light, will be able to carry 3,000 tons of cargo or 2,000 soldiers with their arms. At the trial trip in the Firth of Clyde the steamer proved itself capable of exerting an enormous power, and made seven knots an hour with the barges in tow. The train is to be taken to pieces and reconstructed in India. Messrs. S. and H. Morton, of Leith, have just laid down an iron steamer, 245ft. long, 30ft. beam, and 18ft. hold. She is intended for the Leith and St.

Petersburg trade.

A correspondent to a provincial newspaper makes the following suggestion:-Some time ago a gentleman in London made known his plan of having iron joists and flooring in dwelling houses, so that in the event of a fire the destructive element might be kept

the room where it commenced. The idea is good; but when a fire does take place in a dwelling, in general the staircase, being of wood, goes early. Means of escape are thus cut off: the inmates can neither get down to the street nor up to the trap-door, so as to get on the roof of the next house. Allow me to suggest to builders, ironmasters, and others, the having, not only iron joists and flooring, but also stairs made of cast iron. The one end of the steps may be inserted into the wall, when the house is going from the ground to the top of the house. fast into an upright square or round cast iron pillar, Stairs so made might have carpeting on them, and patterns can be now produced from cast iron. Eyes the steps may be made highly ornamental, as beautiful for the stair carpet rods may be made in the steps.

the date (1858) it appears that he is not the inventor

of the contrivance.

Mr. Babbage has remarked (Economy of Machinery and Manufactures, Art of Copying) that a man named Gonord, a watchmaker of Paris, has invented a method of obtaining impressions of various sizes from one engraving. The suppositions given are, either that the impression was transferred to the surface of water in a conical vessel, which could be raised or lowered, and thus perhaps the impression be diminished, or by imparting a blue colour, produces greys of various depths and hues; and similarly brown and darker rocks and flowed lands seem characterized by the colours olive, sepia, and drab, or the lighter

shades of brown.

wooden head of the cartridge, or the auger that bores the hole in the stump, a heavy blow by a sledge on the projecting head of the bar will explode the cartridge with the fullest effect. It may be employed usefully in breaking up the carcases of old ships, and splitting stumps for firewood.

The Admiralty have come to the determination of abolishing the rank of third-class assistant engineer in the navy. Assistant engineers of the first-class will in future be styled engineers, those who are at present in the second-class will become first-class, and those of the third will be designated second class assistant engineers.

At a recent meeting of the Manchester Philosophical Society, Dr. Grace Calvert stated that in consequence of having found lead in snuff packed in leaden cases, he had examined tea, chicory, &c., but without discovering lead in them, which he attributed to the protection afforded, in some instances, by the interposition of paper between the article and the leaden case, and in others to the absence of sufficient moisture to promote chemical action.

The Times in commenting on the Siege of Gaeta says:-We know so little of the details of this siege that it is difficult to say how far the Piedmontese have shown themselves possessed of military science. The theory of Louis XIV., that the highest qualities of a General were proved in siege operations, while fighting in the field could be directed by average talents, has truth in it so far that many very successful commanders have been repulsed by very ordinary fortifications. We English have generally managed to supply the want of engineering skill or material by sheer courage; and we escaladed Badajoz fifty years since, and captured Delhi the other day, with very little aid from science to smooth the path of the storming parties. Continental armies go to work on a more scientific system, and delay the final assault until resistance has become impossible. The parallels and approaches must be complete, every battery of the place must be enfiladed by the besiegers, large masses of troops must be brought up ready to support the assaulting column, before a modern General thinks it his duty to try the last resources of war. And, thanks to late improvements in gunnery, sieges have become more scientific than ever. The modern taker of cities must be an engineer, a mechanician, perhaps even a chemist; and if he be these he may

At the last meeting of the Numismatic Society, W. S. Vaux, Esq., President, in the chair, Mr. John Evans read a short paper communicated by Sebastian Evans, Esq., M.A., on "Modern Art and the New Bronze Coinage," showing that, as works of art, the new coinage was inferior to any yet produced from the English mint, the similarity and equality of the several portions of the design being one of its gravest faults. The shape of the head is incorrect, particularly in the upper portion of the forehead, and the likeness is very bad. On the reverse, the ship and lighthouse are of exactly equal bulk, precisely balancing each other, and the head of Britannia is ridiculously small. The length of the face is hardly, if at all, greater than the width of the arm near the shoulder, or the length of the hand without the fingers, while the neck is precisely of the same thickness as the upper arm, and the attempt to make up in helmet what is wanting in head, serves to make the deficiency more signal. Altogether, Mr. Evans observed, in both observe and reverse, the design is feebler, and the work less satisfactory, than in any former coin of her Majesty's reign.

The Army and Navy Gazette says:-The experiments now being conducted at Portsmouth, both for the purpose of testing the new heavy rifled cannon, and their effects against iron-cased vessels, have come to a complete standstill by the failure of the guns employed. First, the 100-pounder Armstrong was found defective in the proving, and lately the 80pounder Whitworth has also given out. Practice with the latter had been carried on from the Stork gunboat by Captain Hewlett, of the Excellent, at the Sirius, whose sides are cased with iron armour on the angulated system, and the result of the firing at 300 yards' distance was a penetration of only 24 inches, while the polygonal bolts dropped alongside broken. The firing from the 68-pounder solid shot, smooth