machinery, and to enable you to hold the comparison just, in all cases, recommend that 10 pounds pressure on the square inch of the boiler be adopted as the standard or limit of pressure for the marine condensing engines of the navy, working expansively, and cut off at one-third the length of the stroke.

This will give a constant effective pressure on the square inch of piston of about 9.9 lbs.

To render the comparison between engines of different length of stroke uniform, it will be necessary to establish the velocity in feet for the different lengths of stroke; for which object, as water wheels of large diameter are found more effective, I would propose to adopt 15 revolutions of the water wheel, as the speed for water wheels of about 30 feet diameter = 94 feet circumference at the extreme diameter x 15 revolutions per minute × 84870 feet velocity of exterior of wheel per hour, from which 56.580 5.280

deduct, 28290, 56.580, or

=== 10

7-10 miles per hour through the water, the allowance of one third loss of speed is greater than will be found in practice with vessels of good model; but it is a safe allowance, and I do not think will differ much in the vessels Missouri and Mississippi, now nearly ready. Taking 15 revolutions as the speed of these two steamers, the velocity of the pistons will be as follows:

Mississippi 7 feet stroke x 2 = 14 feet x 15 = 210 feet per minute.

Missouri 10 feet stroke x 2=20 feet x 15 =

Length of stroke

Diameter of water wheel
Number of floats
Depth of floats
Length of floats

4

74in. 10 feet.

The ordinary pressure of steam used by the Great Western is 3 lbs. on the square inch of boiler, and although the arrangement for working expansively is annexed to the engine, I believe the effective pressure of steam will not exceed 8 lbs. on the square inch of piston.

The steam power therefore at 15 revolutions of the water wheel will be as follows: Cylinder 73 in. diameter-area x by velocity 7 × 2 × 15

× by effective pressure

4243

210

891038 8

Horses power of combined engines 432

In the logs of the Great Western's first voyage, published in Bristol on July 4, 1838, the combined power of the engines is rated by Peter Maze, chairman, at a meeting of stockholders, held June 2, 1838, at 450 horses power; but the revolutions per minute in the log fall short of 15, and should rate her power beyond that now stated, 432 horses.

The Great Western's tonnage is rated at 1340 tons, but I have not at the moment

RECENT AMERICAN PATENTS. [Abridged from the Franklin Journal.] SPARK ARRESTER.-Wm. C. Grimes.— The patentee says:-"The nature and principle of my invention consists in giving to the upper part of the chimney of a locomotive or other steam engine, such a form as to cause the gaseous current as it passes through the same, to circulate or revolve around a horizontal, cylindrical screen; tending by this circular or rotary motion to throw all the sparks or other solid particles from the central screen outwards to the walls of the circular or scroll formed chamber, from whence, through proper openings, they escape into an exterior receptacle prepared for the purpose, while the gases readily pass into the central screen, and thence escape at the open ends of it into the atmosphere direct, or through short vertical side-flues constructed for the purpose."

A MACHINE FOR CUTTING INDIA RUBBER

INTO THREADS OR STRIPS.-Day, Tyer, and Helm." The nature of our invention consists in passing the sheet of india rubber over a roller, with or without grooves on channels round it, and cutting it by means of a gang of knives, which are made to vibrate rapidly across-the knives being kept continually wet by the dripping of water upon them."

RE-ACTION WATER WHEEL.-Theodore Timby." The nature of my invention, and the chief characteristics which distinguish it from all other water wheels before known, consist in continuing the hollow arms, through which the water passes, and from which it issues, in a curve eccentric to the curve of that part of the arms which receives the water, and which is concentric with the shaft, the inner and outer peripheries of the eccentric part of the arms being parallel with each other, instead of approaching to each other for the purpose of

19

gradually contracting the channel in the arms towards the issues, as heretofore; this end being attained in my present improvement, by means of a jointed or hinged shutter or valve, regulated by a screw, or other analogous device, by which the channel is not only gradually contracted, but is susceptible of the nicest adjustment, and at the same time affords the means of removing blocks of wood and other obstructions, which frequently enter the channels and are wedged in with great force by the pressure of the water, but which in my wheel may be removed with facility, by simply opening the shutter or valve."

MACHINE FOR BORING OUT THE CYLINDERS OF ROTARY STEAM ENGINES.William Wright.-The patentee says:"The nature of my invention consists in arranging a cutter which, as it rotates with the shaft to cut out the annular groove, receives a slow rotary motion on the arm or flanch which connects it with the shaft, to make the groove a true circle in its cross section."

STOVE FOR HEATING APARTMENTS.— Charles Babcock." The fire chamber of my stove consists of a cylinder of iron, the two ends of which contain hinged grates, or grate bars, upon either of which the fuel is to rest, the two ends being alike. Between the two ends the cylinder may be lined with a bad conductor of heat, if desired. The grate bars are made to raise, so that the set which is uppermost may be opened for the supply of fuel. This cylindrical fire chamber is to be furnished with two gudgeons opposite to each other, and at equal distances from its ends; upon these gudgeons it is to be sustained when in use. I place this cylinder within a vertical drum of such depth from head to head as slightly to exceed the diameter of the cylinder, and of such diameter as will allow the cylinder to revolve within it without touching its periphery. Upon one of the gudgeons upon the outside of the drum, I affix a winch, or crank handle, by means of which the cylinder may be inverted or agitated at pleasure. On the top of the drum I place a box or case, on one side of which there is to be a door for the admission of fuel; and and either from the top, or from one side of this box or case, proceeds a pipe for the exit of smoke and gaseous matter."

IMPROVEMENT IN THE PIANO FORTE.Simon W. Draper." The object of my improvement is to increase the volume of tone, and to augment the harmony, when a chord is struck upon the instrument, by producing with the stroke of each hammer the usual simple tone, and in addition thereto a consonant tone an octave below."

"This object is effected by means of an additional string for each note in the instrument, which is made sufficiently longer than those by which the tone is commonly produced, to produce the octave tone above specified a secondary crooked bridge,' in rear of the ordinary one, being provided for the said additional strings, and some necessary alterations in the construction of the iron frame' and 'back-bridge' being made."

IMPROVEMENT IN THE POWER LOOM.Enoch Burt.-This improvement consists in the employment of a set of fingers jointed to the lay, and playing between fingers or bars in the race board, so that when the shuttle has passed without a thread, the jointed fingers will pass between the bars in the race board and disengage the protection bar and stop the loom.

Claim." In the foregoing described first and second variety of woof protection, I claim as my improvement, and desire the same secured to me accordingly, the hanging of the combs or limbs before described upon the race beam itself in such manner as to sink to the face of the race as the lay moves back to admit the shuttle to pass smoothly over it, and rise immediately after, (if there be no woof thread,) bringing the protecting finger in contact with the latch or cast off, arresting the lay in its first downward progress, and instantly stopping the loom."

IMPROVEMENT IN TAILORS' SHEARS.Herman Wendt.-The improvement consists of a guard piece which is placed across, and forms a connection between the outer and inner part of the thumb bow in such a form and position as to nearly encircle the whole of the ball near to the middle joint of the thumb of the operator, and give that part of the hand a more equal and extended bearing, and preventing the handle from falling into the web of the thumb, thereby enabling the operator to use the instrument more effectively than without this improvement.

IMPROVEMENT IN FORMING WORKED BUTTONS ON THE HEADS OR HANDLES OF WHIPS, &c.-Robert S. Brown.-" In making or forming the buttons by my improved process, I proceed in the following manner: I take the whip maker's plaiting machine, of any of the several kinds now in use; some of these machines, as is well known to manufacturers, require to have a rim or hoop around them which must reach up to the height of the bobbins, to enable them to plait backwards, whilst others do not require this appendage. In using these machines, I form what are called the thumb and top buttons upon a mandrel or spindle of wood, or of metal, of suitable size. For

a foundation upon which to plait the button I make a tube of paper, by pasting one, two or more thicknesses of that material, around that part of the mandrel which is of the proper size. This paper tube I cut square at each end, and to the length required for the button. I then place the mandrel in the machine, and plait over the paper tube from one end of it to the other, and cut the ends of the thread or catgut off smoothly at the place of beginning, I next back over the first plaiting far enough to cover the ends of the threads at the place of beginning, by which they are rendered secure. For some purposes the plaiting will then be completed; but if the button is required to be thicker in whole or in part, I continue to plait backward and forward until it has assumed the desired size and shape. It is then to be taken off the mandrel, the thread or catgut cut off to a proper length, unravelled to a short distance, and tucked into the paper tube, taking care that they do not reach through it. I then pass the mandrel into the tube, roll the button, and size it."

NOTES AND NOTICES.

The

Railway Progress.-The Middleborough and Redcar Railway was opened on the 4th of Juns; and not the least interesting part of the proceedings was incidental to rather than directly arising from the occasion. Mr. Plews, so favourably known in connection with the North of England Railways, and Mr. Hopkins, (two of the directors,) piloted the way with the Number 1 engine of the Stockton and Darlington Railway Company. This is the first locomotive engine to which a passenger-carriage was ever attached. The engine was, of course, made under the direction of Mr George Stephenson; and the passenger carriage (built omnibus fashion, with a table running down the middle) was called the Experiment. This carriage is, we believe, still preserved at Shilden. "No. 1" ran a race in September 1835 with the mail, a distance of four milessteam beating horse-flesh by only a hundred yards! On the opening of the Redcar line, the distance of eight miles occupied with "No. 1" about thirty-five minutes, although only one passenger-carriage and two trucks were attached. At the dinner to celebrate the opening, Mr. Plews noticed the "remarkable coincidence," that the first locomotive and the last (and best) should be in the possession of the two companies connected with the Redcar line, namely, the "No. 1" above referred to, the property of the Stockton and Darlington Company; and the engine A, which ran against the broad-gauge engines in the experiments of

the Gauge Commissioners, and which belongs to the Great North of England Company.-Railway Record.

Proofs that the Moon is not Inhabited.— Dr. Scoresby in an account that he has given of some recent observations made with the Earl of Rosse's leviathan telescope, says:-"With respect to the moon, every object on its surface of the height of 100 feet was now distinctly to be seen; and, he had no doubt, that under very favourable circumstances it would be so with objects 60 feet in height.

On its surface were craters

of extinct volcanoes, rocks, and masses of stones almost innumerable. He had no doubt whatever that if such a building as he was then in were upon the surface of the moon, it would be rendered distinctly visible by these instruments. But there were no signs of habitations such as ours-no vestiges of architectural remains to show that the moon is or ever was inhabited by a race of mortals similar to ourselves. It presented no appearances which could lead to the supposition that it contained any thing like the green fields and lovely verdure of this beautiful world of ours. There was no water visible-not a sea, or a river, or even the measure of a reservoir for supplying town or factory; all seemed desolate."

A Narrow Gauge Monster.-A beautiful engine, called the Atlas, has been constructed by the emiBent locomotive manufacturers, Messrs. Sharp, Brothers, Manchester, for the Bristol and Birmingham Railway Company. This engine has been at work on the line for the last two months, and it has been found capable of maintaining a speed of 58 miles an hour with a train of ten carriages with passengers, over undulating gradients. The weight of this engine and tender is only twenty-five tons, and it is perfectly steady at the highest velocity. We have lately seen an account of about the same velocity having been attained by the new "Monster" engine on the Great Western Railway, weighing with its tender 50 tons, or twice as much as Messrs. Sharp's engine on the narrow gauge. The momentum of an engine is represented by the weight multiplied by the velocity, and the wear and tear of the engine itself and of the rails, as well as the risk of accident from displacement (the usual cause of accidents,) is exactly proportional to the momentum. It is clear that in all these respects, then, as well as in a large economy of first cost, the advantage of the light engine on the narrow gauge over the "Monster" engine on the broad gauge must be taken as nearly two to one. Messrs. Sharp's engine is found to be exceedingly economical in the consumption of fuel.-Times.

New Planet Expected.-The French Academy of Sciences have received a paper from M. Leverrier, the object of which is to prove that there exists in our solar system la large planet which nobody yet has seen, but the orbit of which M. Leverrier has caleulated, and which, he says, may be seen on the 1st of January next year. He states that he was led to his discovery by the observations collected since 1690 on the course of Uranus. The insurmountable difficulty experienced by geometricians, says M. Leverrier, in representing the real course of Uranus by analytical formulæ might arise from various causes. Either the theory was not sufficiently precise, and they had neglected in their calculations some of the influence due to the perturbatory

21

action of the neighbouring planets, Jupiter and Saturn; or the theory had not been compared with the observations with sufficient correctness in the construction of the tables of the planet; or, finally, some unknown cause, acting upon Uranus, added other influences to those which result from the action of the Sun, of Jupiter, and of Saturn. To get out of this alternative, it was necessary to resume the whole theory of Uranus,-recalculate, discuss the observations, and compare them with each other; and this hard task he undertook. The result is, the positive conclusion, that the irregularity of the movement of Uranus is to be attributed to a special cause, independent of all analytical error, and deduced from the constitution of the planetary system itself. The fact of the existence of this cause being established, it was necessary to determine its nature,-and, therefore, a new career opened upon M. Leverrier. Was it admissible, as some astronomers had proposed, to modify the law of gravity for the distant regions in which Uranus moves; or did it suffice to assume the resistance of the other, or the influence of an obscure satellite moving round Uranus, or the accidental shock from a comet? Or was he to admit of a still unknown planet whose existence was shown by the anomalous movement of Uranus? M. Leverrier adopted the latter hypothesis; and proceeding upon that basis, has come to a conclusion, from all his calculations and observations, that no other is possible. This planet, he says, is situated beyond Uranus, at a distance double that which separates Uranus from the Sun, and in a slightly inclined orbit.

LIST OF ENGLISH PATENTS GRANTED BE

TWEEN JUNE 27, and June 30, 1846.

Joseph Storer, of Stanhope-street, Morningtoncrescent, musical-instrument maker, for improvements in organs, seraphines, and other "free reed" instruments, part of which improvements are applicable to pianofortes. June 27.

John Davie Morries Stirling, of Black Grange, North Britain, Esq., for certain new alloys and metallic compounds, with a method of welding the same and other metals. June 29; six months.

François Stanilas Meldon de Sussex, of Millwall, Middlesex, manufacturing chemist, for improvements in the manufacture of soda and potash. June 29; six months.

Thomas Lane Coulson, of Assington Hall, Assington, Suffolk, Esq., for improvements in the construction of chairs. June 29; six months.

Charles Payne, of Whitehall Wharf, Cannon row, Westminster, gentleman, for improvements in preserving vegetable matters. June 29; six months.

William Mill, of Newhall-street, Birmingham, manufacturer, for improvements in instruments used for writing and marking, and in the construction of inkstands. June 29; six months.

Moses Poole, London, gentleman, for improvements in regulating the velocity of steam-engines, being a communication. June 29; six months.

Joseph Moreland, of Old-street, Middlesex, copper, still, and boiler-setter, oven-builder, construcand designer of furnaces generally, for improvements in setting and fixing coppers, stills, and boilers, and in the construction of furnaces. June 29 six months.

William Smith, London, gas-meter manufacturer, for certain improvements in gas-meters. June 29; six months.

Antoine Perpigna, of Paris, advocate, for improvements in regulators for qualifying the actions of mechanical powers, being a communication. June 29; six months.

John Tatham, of Rochdale, Lancaster, machinemaker, David Cheetham, of the same place, machine-maker, and John Wallace Duncan, of Manchester, gent., for certain improvements in machinery, or apparatus, to be used in the prepara

tion and spinning of cotton, and other fibrous substances. June 29; six months.

Joseph Seraphin Faucon, of Rouen, France, banker, for improvements in combining materials to be employed in fulling cloth. June 29; six months.

Sir James Caleb Anderson, of Buttevant Castle, Ireland, baronet, for certain improvements in obtaining motive power, and in applying it to propel carriages and vessels, and to the driving of machinery. June 29; six months.

Thomas Parkin, of Hoxton, Middlesex, engineer, for improvements in the means of giving motion to locomotive carriages, with or without bearing wheels attached to them, and in the construction of ways, passages, and roads, on which the said carriages are to travel. June 29; six months.

Charles Clark, of Cornhill, City, merchant, for certain improvements in the pyro-hydro pneumatic apparatus for generating, purifying, and condensing steam and other vapours, and for obtaining vegetable extracts. June 29; six months.

James Hastings, of Havre, France, for an improved machine for making bricks, tiles, quarries, and cornice ornaments. June 30; two months.

William Clark, of Hoxton, Middlesex, machinist, for certain improvements in weighing machines, steel yards, and scale beams. June 30; six months.

NOTICES TO CORRESPONDENTS. Tithe Surveys.-" Surveyor" must authenticate his denial by his name and address-in confidence if he pleases.

The Supplement to our last volume is this day sublished, and may be had gratis through any bookpeller, or Newsman.

Advertisements.

Patent Window Blinds. TYLOR and PACE manufactures every descrip

tion of Window Blinds entirely upon their own premises, by the aid of steam machinery, ensuring the best materials and workmanship at the lowest cost. Patent metallic gauze and perforated zink blinds, in mahogany frames, at Is. 8d. per square foot.; ditto, in metal frames, 1s. 2d. per square foot. A large and choice assortment of transparencies, mounted, from 19s.; Holland blinds, on plain or spring rollers. Outside shades, Venetian, and sun blinds of every description.-Tylor and Pace's show rooms, 53, Cornhill, entrance St. Peter's-alley.

The Artisan Club on the Steam

Engine.

To Connoisseurs in Shaving.

THE FLEXIBLE RAZOR STROP.-Registered

February 28, 1846.-In introducing this novel and unique strop to the notice of the public, the inventors beg leave to call attention to the peculiarity of its construction, for by a simple yet ingenious mechanical contrivance, i. e., by the application of the principle of the lever, the s'rop is not only rendered flexible, but its flexibility can always be maintained to the extent desired, simply by turning the handle of the spindle to the right hand or to the left, according as it is intended to tighten or relax the strop. Thus is a desideratum, the want of which has long been felt, as the great variety of strops bear witness, at last obtained for the flexibility of the strop, allowing it to yield in proportion to the degree of pressure imparted, its surface will be preserved from indentation, and its action upon the edge of the razor will be always uniform, -a quality so indispensable in a strop, in order to produce that evenness of edge which is essential to ease and comfort in shaving. To be obtained wholesale and retail, at the usual houses in town or country, and of the inventors and manufacturers, T. and G. BARNES, 26, Goswell-street, St. Luke's, Middlesex

Teeth Preserved and Pain
Removed.

HERR VON HELM'S ALMA ANODINA is a certain remedy for toothache, having cured some thousands throughout Holland, France, and Germany. This invaluable preparation has been submitted in England to Dr. C. M. Clark, Bart., M.D., Sir M. Tierney, Bart., M.D., Dr. Chambers, Dr. Paris, and the late Dr. Jas. Johnson, and many other eminent members of the faculty, and been pronounced by them as a great modern discovery, and they have expressed their astonishment at its powerful and beneficial effects on the gums, and its antiseptic qualities in whitening and preserving the teeth, and strenuously recommend its application to all affected with the tooth-ache. Price 2s. 6d. and 5s. per packet. Each packet also contains an enamel stopping, for decayed teeth, which can be applied by the patient, and becomes as hard as the other teeth immediately after use, rendering them again fit for mastication. (This stopping is now used by the most eminent dentists.) Residents in the country, remitting a post-office order for 2s. 8d. or 5s. to Herr Von Helin, Surgeon-Dentist, 39 A, Wigmore-street, Cavendish-square, will receive a packet with directions by return of post. Herr Von Helm can be consulted, at his residence as above, daily, from 10 to 5, on his new method of applying artificial teeth, from one to a complete set, by a system of self-adhesion, avoiding the use of springs, improving articulation, and fully restoring the power of mastication, which is so important to health.-Herr Von Helm, Surgeon-Dentist to the King of the Netherlands, 39 A, Wigmore-street, Cavendish-square.

Templeton's Practical Works.

MILI

Lately published, price Five Shillings, the ILLWRIGHT and ENGINEER'S POCKET COMPANION; comprising Decimal Arithmetic, Tables of Square and Cube Roots, Practical Geometry, Mensuration, Strength of Materials, Mechanic Power, Water Wheels, Pumps, and Pumping Engines, Steam Engines, Tables of Specific Gravity, &c., &c. To which is added, an APPENDIX, containing the Circumferences, Squares, Cubes, and Areas of Circles, Superficies and Solidities of Spheres, &c., &c. By WILLIAM TEMPLETON. Seventh Edition.

"Nearly all the authors I have consulted dress up their rules in the garb of algebraical formula, which, to the majority of plain practical men, is perfectly unintelligible, and Mr. Templeton, by avoiding that system, has made a book more useful